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                                                                     EXHIBIT 2.1




                            STOCK PURCHASE AGREEMENT


                    This Stock Purchase Agreement ("Agreement"), dated as of
August 20, 1999, is by and between CSK Auto, Inc., an Arizona corporation
("Purchaser"), and PACCAR Inc, a Delaware corporation ("Seller").

                    Seller is interested in selling and Purchaser is interested
in purchasing all of the issued and outstanding shares of stock of PACCAR
Automotive, Inc.

         NOW, THEREFORE, Seller and Purchaser agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

         As used herein, the following terms shall have the following meanings:

         1.1 Assumed Liabilities. The term "Assumed Liabilities" means those
liabilities described in Section 2.2 hereof.

         1.2 Benefit Plan. The term "Benefit Plan" means any collective
bargaining agreement or any bonus, pension, supplemental pension, profit
sharing, deferred compensation, incentive compensation, stock ownership, stock
purchase, stock option, phantom stock, retirement, vacation, severance,
disability, death benefit, hospitalization, medical dependent care, cafeteria,
employee assistance, scholarship program, computer purchase or other plan,
arrangement or understanding (whether or not legally binding) providing benefits
to any Employees, former employees or directors of the Company, except for the
Excluded Assets and Liabilities.

         1.3 Closing Date. The "Closing Date" means September 25, 1999. If the
expiration of the waiting period under the Hart-Scott-Rodino Anti-Trust
Improvements Act of 1976, as amended ("HSR Act"), occurs after September 22,
1999, then the Closing Date shall be the fifth business day after the date on
which the waiting period expires, unless Seller or Purchaser has terminated this
Agreement under Section 10.1. The Closing Date may be changed by mutual
agreement of the parties.

         1.4 Code. The term "Code" means the Internal Revenue Code of 1986, as
amended.

         1.5 Company. The term "Company" shall mean PACCAR Automotive, Inc., but
excluding its wholly owned subsidiary PACCAR Automotive Distribution Company
("PADC").

         1.6 Company Assets. The term "Company Assets" means all of the
Company's properties, assets, rights, obligations and liabilities, whether
tangible or intangible, real or personal, known or unknown, fixed or contingent
or otherwise, as of the Closing Date (except the Excluded Assets and
Liabilities) and which are used or have arisen in connection with the business
of the Company, including without limitation, the following:

                  1.6.1 All real property and improvements, and the interests in
         real property under any option or lease ("Real Property"), which are
         further identified on Schedule 1.6.1 hereto, except for the Excluded
         Assets and Liabilities;

                  1.6.2 All equipment (including without limitation, all office
         equipment), fixtures,
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         trade fixtures, furniture, inventory racks and other tangible property
         of any kind, except for the Excluded Assets and Liabilities;

                  1.6.3 All inventories of the Company;

                  1.6.4 All office and other miscellaneous supplies of the
         Company;

                  1.6.5 All rights, liabilities and obligations existing under
         leases of personal property (both as lessor and as lessee), contracts,
         options, licenses, permits, sales agreements, purchase agreements,
         vehicle lease agreements, and all other agreements and business
         arrangements entered into in the normal course of business
         ("Contracts"), except for the Excluded Assets and Liabilities. The
         Contracts are further described on Schedule 1.6.5 hereto by category,
         with each Contract with an outstanding obligation in excess of $50,000
         identified separately;

                  1.6.6 All registered and unregistered trademarks, service
         marks, trade names and similar rights to names, marks and slogans,
         common law and registered copyrights which are further identified on
         Schedule 1.6.6 hereto, and all applications for any of the foregoing,
         together with all rights to use all of the foregoing forever, and all
         goodwill associated with any of the foregoing, except for the Excluded
         Assets and Liabilities;

                  1.6.7 All computer software resident on computers included in
         the Company Assets and used solely for the business of the Company,
         except the Excluded Assets and Liabilities, provided that Company has
         the legal right to continue using such software after a change in
         ownership of Company;

                  1.6.8 All bank and trust accounts, accounts receivable
         (including credit card receivables) of the Company and the opening cash
         balances for each store as set forth on Schedule 1.6.8, except the
         Excluded Assets and Liabilities;

                  1.6.9 All deposits and prepayments or prepaid expenses
         reflected on the Statement of Net Assets, except the Excluded Assets
         and Liabilities;

                  1.6.10 All of the Company's records pertaining to customers,
         suppliers or personnel and all other files and business records of
         every kind, including financial records;

                  1.6.11 All advertising materials and all other printed or
         written materials, except for the Excluded Assets and Liabilities;

                  1.6.12 All governmental and other licenses, permits,
         franchises, approvals and certificates, to the extent transferable;

                  1.6.13 All goodwill, including that arising from business
         acquisitions, and all other intangible properties; and

                  1.6.14 All other assets and liabilities of the Company not
         referred to in 1.6.1 to 1.6.13 above which are reflected or noted on
         the Statement of Net Assets or have arisen in the ordinary course of
         the business of the Company, except for the Excluded Assets and
         Liabilities.

         1.7 Company Stock. The term "Company Stock" means all of the issued and
outstanding shares of stock of the Company.

         1.8 Damages. The term "Damages" means any and all liabilities, losses,
damages, demands, assessments, claims, awards, judgments, penalties,
settlements, fines, interest, costs and expenses (including, without limitation,
reasonable fees and expenses of attorneys, consultants and other professionals
incurred in connection with investigating and defending any claims or causes of
action), but excluding incidental, consequential (including without limitation
loss of profits or loss of business
<PAGE>   3
opportunities), punitive or exemplary damages, other than those imposed in
connection with a third party claim.

         1.9 Employees. The term "Employees" means all of the employees of the
Company on the Closing Date, including all employees of PADC (who shall be
transferred to and become employees of the Company prior to the Closing Date),
but excluding all employees at the Oakland Distribution Center ("Oakland D. C.
Employees") (who shall be transferred to and become employees of Seller or an
affiliate of Seller prior to the Closing Date).

         1.10 Encumbrance. The term "Encumbrance" means any security interest,
mortgage, pledge, trust, claim, lien, charge, option, defect, restriction,
encumbrance or other right or interest of any third party of any nature
whatsoever.

         1.11 Environmental Laws. The term "Environmental Laws" means any and
all laws, statutes, ordinances, rules, regulations, orders, or determinations of
any Governmental Entity pertaining to health, safety or the environment
applicable to (i) the Company's business or operations, (ii) the Company Assets,
or (iii) the disposal of any hazardous substance by the Company, including, but
not limited to, the Clean Air Act, as amended, the Comprehensive Environmental,
Response, Compensation, and Liability Act of 1980 ("CERCLA"), as amended, the
Federal Water Pollution Control Act, as amended, the Resource Conservation and
Recovery Act of 1976, as amended ("RCRA"), the Safe Drinking Water Act, as
amended, the Toxic Substances Drinking Water Act, as amended, and the Superfund
Amendments and Reauthorization Act of 1986, as amended. The term "hazardous
substance" has the meaning specified in CERCLA, and the term "disposal" (or
"disposed") has the meaning specified in RCRA; provided that, to the extent the
laws of the state in which any Company Assets are located establish a meaning
for "hazardous substance" or "disposal" which is broader than that specified in
CERCLA or RCRA, such broader meaning shall apply with respect to such assets in
such state.

         1.12 Excluded Assets and Liabilities. The term "Excluded Assets and
Liabilities" means the following assets and any related liabilities and
obligations of the Company as of the Closing Date, whether tangible or
intangible, real or personal, known or unknown, fixed or contingent or
otherwise, which are not included in the Company Assets and will not be acquired
by Purchaser hereunder, all of which are described below:

                  1.12.1 The Oakland Distribution Center ("Oakland D. C.") and
         all other real property and interests in real property listed in
         Schedule 1.12.1 attached hereto, together with any improvements,
         fixtures, equipment, supplies or other personal property used in
         connection therewith, and contracts for services to support the
         operations of such real property;

                  1.12.2 All computer software licensed under a master agreement
         with Seller or any affiliate of Seller (other than the Company) or
         resident on any computer not owned or leased by the Company, even if it
         is also used by the Company;

                  1.12.3 All bank and trust accounts listed on Schedule
         1.12.3(a), all cash in the bank accounts listed in Schedule 1.12.3(b)
         and all cash and checks (but not credit card receivables) received on
         or before the Closing Date;

                  1.12.4 All intercompany receivables and payables between
         Seller and Company;

                  1.12.5 Federal and state income taxes pertaining to or
         attributable to the Company with respect to any and all taxable periods
         or portions thereof ending on or before the Closing Date and any taxes
         attributable to the transfer of assets to, or liabilities between, the
         Seller and the Company pursuant to this Agreement;

                  1.12.6 All letters of credit ("LC's") established by Seller or
         relying on the credit of Seller for the benefit of Company listed on
         Schedule 1.12.6;
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                  1.12.7 Any amounts owing to any Employees under any deferred
         compensation plan maintained by Seller for any period prior to the
         Closing and which is not transferred to Purchaser under the terms of
         this Agreement;

                  1.12.8 All Seller proprietary items including without
         limitation internal telephone directories, Seller trademarked items,
         Seller promotional materials, compliance and policy materials, and
         similar items;

                  1.12.9 The trademarks, service marks, trade names and all
         similar rights to the names, marks and slogans which are further
         identified on Schedule 1.12.9 hereto.

                  1.12.10 The office and computer equipment, fixtures, furniture
         and other tangible property listed on Schedule 1.12.10 hereto;

                  1.12.11 The sponsorship of and all assets and liabilities
         related to the Company and Seller Benefit Plans listed on Schedule
         1.12.11;

                  1.12.12 The settlement proceeds from the claims listed on
         Schedule 1.12.12;

                  1.12.13 Any deferred intercompany gain as defined in Treasury
         Regulation Section 1.1502-13;

                  1.12.14 All liabilities of the Company or the Seller in
         respect of the Oakland D.C. Employees;

                  1.12.15 All of the capital stock of PADC; and

                  1.12.16 All obligations and liabilities in the lawsuit
         captioned U.S. Engine v. PACCAR Automotive, Inc., presently pending in
         King County, WA.

         1.13 Final Statement of Net Assets. The term "Final Statement of Net
Assets" means the final statement of net assets of the Company, prepared as set
forth in Section 3.3, as of the Closing Date. The Final Statement of Net Assets
shall include reserve amounts that have been determined in accordance with GAAP
and calculated in a manner consistent with those shown on Schedule 1.18(b).

         1.14 GAAP. The term "GAAP" means United States generally accepted
accounting principles as they apply to a statement of net assets for a
subsidiary with exceptions consistent with those used for the preparation of the
Statement of Net Assets. GAAP does not include footnote disclosures required by
generally accepted accounting principles.

         1.15 Governmental Entity. The term "Governmental Entity" means the
United States of America and any state, county, city, municipality and any
subdivision thereof, and any court, administrative or regulatory agency,
commission, department or other governmental authority or instrumentality.

         1.16 Material Adverse Effect. The term "Material Adverse Effect" means
an adverse change in the financial condition, business or operations of the
Company which, when taken together with all other matters having a similar
effect, is materially adverse, or will result in a change which is materially
adverse, to the Company.

         1.17 Net Assets. The term "Net Assets" means, with reference to the
Statement of Net Assets and Final Statement of Net Assets, the difference
between total assets and total liabilities (including deferred income tax
liabilities and capital lease obligations) of the Company determined in
accordance with GAAP; provided, however, (i) there shall be excluded from the
calculation of Net Assets the Excluded Assets and Liabilities, (ii) there shall
be excluded from the calculation of Net Assets for the Final Statement of Net
Assets any increase or decrease in the items listed on Schedule 1.17 from the
amounts shown for such items on the Statement of Net Assets or Schedule 1.18(b);
and (iii) the Assumed Liabilities (as defined
<PAGE>   5
in Section 2.2 hereof) shall be included and specifically identified in the
calculation of Net Assets for the Final Statement of Net Assets.

         1.18 Statement of Net Assets. The term "Statement of Net Assets" means
the adjusted statement of net assets of the Company as of June 25, 1999, which
is attached as Schedule 1.18(a) hereto. Adjustments to the Statement of Net
Assets for Excluded Assets and Liabilities and corporate reserves are also
described in Schedule 1.18(a). The Statement of Net Assets also includes the
reserves described on Schedule 1.18(b).

         1.19 Taxes. The term "Taxes" means all federal, state, local, foreign
and other taxes, assessments or duties, including, but not limited to, all
income, gross receipts, ad valorem, sales, use, franchise, transfer, profits,
value added, withholding, payroll, employment, excise, estimated severance,
property, windfall profits and other taxes, assessments or duties of any kind
whatsoever, imposed or collected by any Governmental Entity or pursuant to any
governmental requirement, together with any interest, penalty, addition to tax,
fine or other additional amounts imposed thereon or related thereto, and the
term "Tax" means any one of the foregoing items.

         1.20 Tax Returns. The term "Tax Returns" means all returns (including
information returns), declarations, reports, statements and other documents of,
relating to, or required to be filed in respect of, any and all Taxes and the
term "Tax Return" shall mean any one of the foregoing Tax Returns.


                                   ARTICLE II

             PURCHASE OF COMPANY STOCK AND ASSUMPTION OF LIABILITIES

         2.1 Purchase of Company Stock. Upon the terms and subject to the
conditions contained herein, Seller will sell, transfer, assign and deliver to
Purchaser and Purchaser will acquire the Company Stock, free and clear of all
Encumbrances, effective as of the end of business on the Closing Date.

         2.2 Obligations and Liabilities Assumed by Company. Purchaser shall
assume (or shall cause the Company to assume), effective as of the close of
business on the Closing Date, all of the obligations and liabilities of Seller
with respect to the Company, the Company Assets and the Company's business
except for the Excluded Assets and Liabilities (the "Assumed Liabilities"),
including without limitation:

                  2.2.1 all liabilities and obligations accruing or becoming due
         or payable to the Employees after the Closing Date (even if the claim
         arose or relates to a period prior to the Closing Date) for
         compensation or other benefits related to the employment or termination
         of employment of such Employees, including without limitation,
         liabilities and obligations, if any, for worker's compensation,
         unemployment compensation or termination of employment benefits, or
         under any Benefit Plans, annuities or employment contracts; and

                  2.2.2 all guarantees, loans, commitments, contracts and other
         obligations made or entered into by Company or Seller in connection
         with the business and operations of Company.

         2.3 Obligations and Liabilities Assumed by Seller. Seller shall assume,
effective as of the close of business on the Closing Date, all Excluded Assets
and Liabilities. Seller shall indemnify, defend and hold the Company and the
Purchaser harmless (according to the provisions of Section 9.8 hereof) from all
Damages, (whether or not arising out of third-party claims) arising from or
otherwise related to any of the Excluded Assets and Liabilities.

         2.4 Purchase Price and Adjustment. Upon the terms and subject to the
conditions contained herein, the purchase price for the sale, transfer,
assignment, conveyance and delivery of the Company Stock ("Purchase Price")
shall be One Hundred Forty Three Million One Hundred Fifty Thousand Dollars
($143,150,000.00). There shall be an adjustment to the Purchase Price equal to
the absolute value of the
<PAGE>   6
amount remaining after the value of the "Net Assets" shown on the Statement of
Net Assets is subtracted from the value of the "Net Assets" shown on the Final
Statement of Net Assets, provided that there shall be no adjustment unless such
difference exceeds $500,000 and then the adjustment shall only be for such
excess. If the difference is positive, Purchaser shall pay the adjustment to
Seller; if it is negative, Seller shall pay the adjustment to Purchaser. Payment
of any amount due in adjustment of the Purchase Price hereunder shall be paid by
wire transfer of immediately available funds to the account designated by Seller
or Purchaser, as the case may be. Any adjustment to the Purchase Price shall be
received within five days after the acceptance of the Final Statement of Net
Assets pursuant to Section 3.3.


                                   ARTICLE III

                                     CLOSING

         3.1 Closing. The Closing of the transactions contemplated herein (the
"Closing") shall be held on the Closing Date at Seller's corporate offices in
Bellevue, Washington. If the Closing Date is not a business day, the Closing
shall be held on the next business day following the Closing Date, and the
Purchase Price shall include interest from the Closing Date to the actual
Closing at the rate of 6% per annum prorated on an actual days basis.

         3.2 Deliveries at Closing.

                  3.2.1 The Purchase Price shall be paid by Purchaser to Seller
         on the Closing Date in immediately available funds, by wire transfer to
         Seller's account as designated by Seller in writing prior to the
         Closing.

                  3.2.2 To effect the transfers referred to in Article II
         hereof, Seller will deliver to Purchaser on the Closing Date:

                           (i) All certificates for the Company Stock and duly
                  executed stock assignment(s);

                           (ii) All of the Company's books, records and files
                  not already located at the Company's offices;

                           (iii) Any other instruments reasonably requested by
                  Purchaser to vest in Purchaser good and marketable title to
                  the Company Stock and any Company Assets; and

                           (iv) The Transition Agreement (as defined in Section
                  9.11).

         All instruments executed and delivered to Purchaser pursuant hereto
         shall be reasonably satisfactory to Purchaser in form and substance.

         3.3 Final Statement of Net Assets.

                  3.3.1 The amount for "Net Assets" shown on the Statement of
         Net Assets and on the Final Statement of Net Assets has been and shall
         be, respectively, determined consistently by Seller from the books and
         records of the Company and in accordance with GAAP, but subject to the
         limitations on adjustment set forth in Section 1.17 hereof.

                  3.3.2 As soon as practicable after the Closing Date (but in no
         event later than 30 days thereafter), Seller shall deliver the Final
         Statement of Net Assets to Purchaser. Purchaser shall allow Seller
         reasonable access to the Company's facilities, books and records and
         shall cooperate with Seller as necessary to allow Seller to prepare the
         Final Statement of Net Assets. Purchaser may, at its expense, review
         the Final Statement of Net Assets, and Purchaser shall have access to
<PAGE>   7
         the work papers used in preparing the Final Statement of Net Assets.
         Purchaser shall have the right to object, by written notice to Seller,
         to the amount set forth as the "Net Assets" on the Final Statement of
         Net Assets, if Purchaser's review reveals that (i) the amounts included
         on the Final Statement of Net Assets for the accounts receivable,
         accounts payable, inventories, or any other assets (except for items
         listed on Schedule 1.17 hereof) are not equal to the amounts which
         should have been included for such items to conform to GAAP as applied
         in the preparation of the Statement of Net Assets or (ii) the amounts
         included on the Final Statement of Net Assets for the liabilities
         (except for items listed on Schedule 1.17 hereof) are not equal to the
         amounts which should have been included for such items to conform to
         GAAP. If Purchaser does not give Seller such notice within 20 days
         after receipt of the Final Statement of Net Assets, Purchaser shall be
         deemed to have accepted the Final Statement of Net Assets for all
         purposes of this Agreement.

                  3.3.3 If Purchaser does give Seller notice of an objection,
         Purchaser and Seller shall meet to resolve the objections. If disputes
         with respect to the Final Statement of Net Assets cannot be resolved
         within 30 calendar days after Purchaser's delivery of a notice of
         objection, then, at the request of Purchaser or Seller, the specific
         matters in dispute shall be submitted to Arthur Andersen or such other
         independent accounting firm as may be approved by Seller and Purchaser.
         Such accounting firm shall render its opinion as to the matters
         submitted to it, and its determination shall be final and binding on
         the parties hereto. The fees and expenses of such accounting firm shall
         be borne one-half by Seller one-half by Purchaser.

         3.4 Assumption of Liability Documents.

                  3.4.1 Upon the reasonable request of Seller and subject to the
         terms and conditions contained herein, Purchaser shall or shall cause
         the Company to deliver to Seller on the Closing Date or at any time
         thereafter any documents reasonably requested by Seller to evidence
         Purchaser's or Company's assumption of the Assumed Liabilities. All
         such documents shall be reasonably satisfactory to Seller and Purchaser
         in form and substance.

                  3.4.2 Upon the reasonable request of Purchaser and subject to
         the terms and conditions contained herein, Seller shall deliver to
         Purchaser on the Closing Date or at any time thereafter any documents
         reasonably requested by Purchaser evidencing Seller's assumption of the
         Excluded Assets and Liabilities. All such documents shall be reasonably
         satisfactory to Seller and Purchaser in form and substance.


                                   ARTICLE IV

                    REPRESENTATIONS AND WARRANTIES OF SELLER

         Seller hereby represents and warrants to Purchaser that:

         4.1 Organization of Seller. Seller is duly organized, validly existing
and in good standing under the laws of the State of Delaware.

         4.2 Organization of Company. Company is duly organized, validly
existing and in good standing under the laws of the State of Washington, and has
full corporate power and authority to conduct its business as it is presently
being conducted and to own and lease its properties and assets. Company is duly
qualified to do business as a foreign corporation and is in good standing in
every jurisdiction in which the nature of the business conducted by it or the
character or location of the properties owned or leased by it makes such
qualification necessary. The articles of incorporation and the by-laws and all
amendments thereto, and the minute books, stock ledgers and stock transfer
records of Company furnished to Purchaser for review are accurate and complete.
Except for PADC, there is no other entity: (i) of which Company beneficially
owns, directly or indirectly, any outstanding stock or other ownership interests
of such entity; (ii) of which Company may be deemed to be in control because of
factors or relationships other than the quantity of stock or other interests
owned; (iii) in respect of which Company may be liable under any
<PAGE>   8
circumstances for the payment of additional amounts with respect to its
interest, whether in the form of assessments, capital calls, installment
payments, general partner liability or otherwise; or (iv) in which Company's
investment is accounted for by the equity method. There is no partnership or
joint venture agreement or arrangement to which Company is a party.

         4.3 Authorization. Seller has full corporate power and authority to
enter into this Agreement, to consummate the transactions contemplated hereby
and to perform its obligations hereunder. The execution, delivery and
performance of this Agreement and the consummation of the transactions
contemplated hereby by Seller have been duly authorized by all requisite
corporate action on the part of Seller, and no approval of the stockholders of
Seller is required in connection herewith. When this Agreement has been duly
executed and delivered by Seller, it will be a valid and binding obligation of
Seller enforceable against it in accordance with its terms.

         4.4 No Conflict or Violation. Neither the execution and delivery of
this Agreement nor the consummation of the transactions contemplated hereby will
result in (i) a violation of or a conflict with any provision of the Certificate
of Incorporation or Bylaws of Seller or the Company, (ii) a breach of or a
default under any term or provision of any contract, agreement, lease,
commitment, license, franchise, permit, authorization or concession to which
Seller or the Company is a party or an event which with notice, lapse of time,
or both, would result in any such breach or default, or (iii) a violation by
Seller or the Company of any statute, rule, regulation, ordinance, code, order,
judgment, writ, injunction, decree, or award, or an event which with notice,
lapse of time, or both, would result in any such violation.

         4.5 Title to Company Stock. Seller has good and marketable title to the
Company Stock, and the Company Stock will be transferred to Purchaser free and
clear of all Encumbrances. There are no outstanding options, warrants,
convertible securities, calls, rights, commitments, preemptive rights,
agreements, arrangements or understandings of any character obligating the
Company (i) to issue, deliver or sell, or cause to be issued, delivered or sold,
additional shares of capital stock of the Company or any securities or
obligations convertible into or exchangeable for such shares or (ii) to grant,
extend or enter into any such option, warrant, convertible security, call,
right, commitment, preemptive right, agreement, arrangement or understanding
described in clause (i) above.

         4.6 Financial Records.

                  4.6.1 Seller has delivered to Purchaser the Statement of Net
         Assets, and will deliver to Purchaser the Final Statement of Net
         Assets, each of which has been or will be prepared (as the case may be)
         in accordance with GAAP, except as otherwise provided in this
         Agreement.

                  4.6.2 Seller has made and kept (and will make and keep) books,
         records and accounts which accurately and fairly reflect in reasonable
         detail its activities and the transactions and dispositions of its
         assets for the period following the preparation of the Statement of Net
         Assets.

                  4.6.3 Since [June 25, 1999] the Company has conducted its
         business in the ordinary course, has maintained the Company Assets in
         at least as good order and condition as existed on the such date (other
         than wear as may be accounted for by reasonable use) and as is
         necessary to continue to conduct their business and has not experienced
         any change or circumstance that would have a Material Adverse Effect.

                  4.6.4 The consolidated statement of operating income of the
         Company attached hereto as Schedule 4.6.4 has been prepared in
         accordance with GAAP consistent with PACCAR's allocation of expenses to
         the Company and fairly present, in all material respects, the
         consolidated results of operations of the Company for the periods
         covered thereby.

         4.7 Company Assets. The Company owns all of the Company Assets, other
than those that are leased, with respect to which it has valid and enforceable
leases. None of the Company Assets is subject to any Encumbrance, except as
reflected on the Statement of Net Assets or Schedule 4.7 and those which
individually or in the aggregate do not exceed $100,000.
<PAGE>   9
         4.8 Real Property. Schedule 1.6.1 hereto contains a description of all
Real Property that is owned or leased by Company, except for the Excluded Assets
and Liabilities. Company has good and marketable title to all Real Property
owned by the Company, and such Real Property is owned free and clear of all
Encumbrances, except for Encumbrances of record or as noted on Schedule 4.8
hereto.

         4.9 Certain Agreements. Except as set forth in Schedule 4.9, neither
Company nor any of the Company Assets is a party to or bound by any agreement,
contract or commitment (i) relating to the borrowing of funds, (ii) relating to
any loan or advance to, or investment in, any person or entity or any agreement,
contract, commitment or understanding relating to the making of any such loan,
advance or investment, (iii) relating to any guarantee or financial assurance of
any obligation or other contingent liability with respect to any indebtedness or
obligation of any person or entity, (iv) relating to any management service,
employment, severance, consulting or other similar type contract or agreement,
(v) that would limit the freedom of the Company or Purchaser, or any affiliate
thereof, following the Closing, to engage in any line of business, to own,
operate, sell, transfer, pledge or otherwise dispose of or encumber any of their
respective assets or to compete with any person or entity or to engage in any
business or activity in any geographic area, or (vi) obligating the Company to
provide indemnification or contribution with respect to any matter outside the
ordinary course of business.

         4.10 Contracts. Except as otherwise disclosed in Schedule 4.10 hereto,
neither Company nor Seller has received any written notice of default or breach
with respect to any Contract, and to the best of Seller's knowledge and belief
there exists no breach or default under any Contract, and no event has occurred
which constitutes, or would constitute with the lapse of time or the giving of
notice, a breach or default under any such Contract.

         4.11 Trademarks, Etc. To the best of Seller's knowledge and belief,
Schedule 1.6.6 hereto contains a true and complete list of all of the
trademarks, trade names, service marks and copyrights, and applications
therefor, which are used in connection with the business of the Company, except
for the Excluded Assets and Liabilities.

         4.12 Accounts Receivable. The accounts receivable and other receivables
of the Company represent bona fide indebtedness arising out of the ordinary
course of business, and to the best of Seller's knowledge and belief, except as
otherwise disclosed in Schedule 4.12 hereto, all such receivables will be
collectable according to their terms and at the book amounts thereof, less any
reserve for bad debts shown on the Statement of Net Assets.

         4.13 Litigation and Proceedings. Schedule 4.13 hereto contains a list
and brief description of all litigation relating to product or general
liability, warranty and other claims, actions, or other proceedings pending, and
to the best of Seller's knowledge and belief, threatened against or otherwise
affecting the Company and which involve any claim for injunctive relief or for
damages in excess of $15,000.

         4.14 Licenses, Permits and Authorizations. Except as otherwise
disclosed in Schedule 4.14 hereto, the Company has obtained all approvals,
authorizations, consents, licenses, franchises, orders and other permits and has
made all filings with any Governmental Entity which are required for the conduct
of the business of the Company as presently being conducted, except those where
the failure to have any such approval, authorization, consent, license,
franchise, order or permit would not have a Material Adverse Effect.

         4.15 Compliance with Law. Except as otherwise disclosed in Schedule
4.15 hereto, the Company is in compliance in all material respects (i.e., where
noncompliance would have a Material Adverse Effect) with all applicable
statutes, rules, regulations, ordinances, codes, orders, licenses, franchises,
permits, authorizations and concessions, as such apply to the Company.

         4.16 Environmental Condition.

                  4.16.1 Except as otherwise disclosed in Schedule 4.16 hereto,
         as of the Closing Date
<PAGE>   10
         there is and will be no contamination of the soil and groundwater of
         the Real Property which would serve as a basis for claims for injury to
         third persons, damage to property of others or claims by governmental
         agencies requiring remediation of contamination on such property.

                  4.16.2 Except as otherwise disclosed in Schedule 4.16 hereto,
         the Company is in compliance with all applicable limitations,
         restrictions, conditions, standards, prohibitions, requirements and
         obligations of Environmental Laws and any related orders of any
         Governmental Entity, except where the failure to so operate in
         compliance would not have a Material Adverse Effect.

                  4.16.3 Except as listed on Schedule 4.16, there are no
         existing, pending or, to the best knowledge of Seller, threatened
         actions, suits, claims, investigations, inquiries or proceedings by or
         before any Governmental Entity directed against the Company or any of
         the Company Assets which pertain or relate to (i) any remedial
         obligations under any applicable Environmental Law, (ii) violations of
         any Environmental Law, (iii) personal injury or property damage claims
         relating to the release of hazardous substances or (iv) response,
         removal or remedial costs under CERCLA or any similar state law.

         4.17 Pension and Benefit Plans.

                  4.17.1 Schedule 4.17 contains a list and brief description of
         all "employee pension benefit plans" (as defined in Section 3(2) of
         ERISA) (sometimes referred to herein as "Pension Plans"), "employee
         welfare benefit plans" (as defined in Section 3(1) of ERISA) and all
         other Benefit Plans maintained, or contributed to, by the Company for
         the benefit of any Employees, except for the Excluded Assets and
         Liabilities. Seller has made available to Purchaser true, complete and
         correct copies of (i) each Benefit Plan (or, in the case of any
         unwritten Benefit Plans, descriptions thereof), (ii) the most recent
         three annual reports on Form 5500 filed with the IRS with respect to
         each Benefit Plan (if any such report was required), (iii) the most
         recent IRS determination letter, if any, and any rulings or
         determinations requested subsequent to the date of that letter, (iv)
         the most recent actuarial report for each Benefit Plan for which an
         actuarial report is required, (v) the most recent summary plan
         description for each Benefit Plan for which such summary plan
         description is required and each summary of material modifications
         prepared after the last summary plan description, (vi) each trust
         agreement and group annuity contract relating to any Benefit Plan and
         (vii) all material correspondence for the last three years with the IRS
         or Department of Labor relating to plan qualification, filing of
         required forms, or pending, contemplated or announced plan audits. No
         Pension Plan maintained or contributed to by the Company is, or has
         been during the last five years, subject to any enforcement action
         under Title IV of ERISA or Section 412 of the Code.

                  4.17.2 Except as set forth in Schedule 4.17, all Pension Plans
         have been the subject of determination letters from the IRS to the
         effect that such Pension Plans are qualified and exempt from Federal
         income taxes under Section 401(a) and 501(a), respectively, of the Code
         and no such determination letter has been revoked nor, to the best
         knowledge of Seller, has revocation been threatened, nor has any such
         Pension Plan been amended since the date of its most recent
         determination letter or application therefor in any respect that would
         adversely affect its qualification.

                  4.17.3 Except as set forth in Schedule 4.17, each Benefit Plan
         that has been or is sponsored, participated in or contributed to by the
         Company: (i) is in compliance in all material respects with all
         reporting and disclosure requirements of ERISA, including, but not
         limited to, Part 1 of Subtitle B of Title I of ERISA, (ii) has had the
         appropriate Form 5500 filed timely for each year of its existence, if
         required, (iii) has at all times complied with the bonding requirements
         of Section 412 of ERISA, if required, and (iv) to the knowledge of
         Seller, has no controversy pending with any Governmental Entity (other
         than the payment of benefits in the normal course and controversies
         disclosed on Schedule 4.17, nor any controversy resolved adversely to
         the Company, which may subject the Company to the payment of any
         penalty, interest, tax or other
<PAGE>   11
         obligation.

                  4.17.4 All voluntary employee benefit associations under
         United States law of the Company have been submitted to and approved as
         exempt from Federal income tax under Section 501 (c)(9) of the Code by
         the IRS.

                  4.17.5 Except as set forth in Schedule 4.17, the execution of
         this Agreement or the consummation of the transactions contemplated by
         this Agreement will not give rise to any, or trigger any, change of
         control, severance or other similar provision in any Benefit Plan.

                  4.17.6 Except as set forth in Schedule 4.17, the Company does
         not provide employee post-retirement medical or health coverage or
         contribute to or maintain any employee welfare benefit plan which
         provides for health benefit coverage following termination of
         employment except as is required by Section 4980B(f) of the Code or
         other applicable statute, nor has it made any representations,
         agreements, covenants or commitments to provide that coverage.

                  4.17.7 Except as set forth in Schedule 4.17, to the best
         knowledge of Seller, none of the Company, any officer of the Company or
         any of the Benefit Plans which are subject to ERISA, including the
         Pension Plans, or any trusts created thereunder, or any trustee or
         administrator thereof, has engaged in a "prohibited transaction" (as
         such term is defined in Sections 406, 407 or 408 of ERISA or Section
         4975 of the Code) or any other breach of fiduciary responsibility that
         could subject the Company or any officer of the Company to any material
         tax or penalty on prohibited transactions imposed by such Section 4975
         or to any material liability under Section 502(l)(1) of ERISA.

                  4.17.8 With respect to any Benefit Plan that is an employee
         welfare benefit plan, (i) no such Benefit Plan includes a welfare
         benefits fund, as such term is defined in Section 419(e) of the Code
         and (ii) each such Benefit Plan that is a group health plan, as such
         term is defined in Section 5000(b)(1) of the Code, complies in all
         material respects with the applicable requirements of Section 4980B(f)
         of the Code.

                  4.17.9 In accordance with applicable law and the terms of the
         plan, each Benefit Plan can be amended or terminated at any time,
         without consent from any other party and without liability other than
         for benefits accrued as of the date of such amendment or termination.

                  4.17.10 No reportable event within the meaning of ERISA
         Section 4043 has occurred or, as of the Closing Date, may be reasonably
         expected to occur with respect to any Benefit Plan. With respect to the
         Benefit Plans, individually and in the aggregate, no event has
         occurred, and to the knowledge of Seller, there exists no condition or
         set of circumstances in connection with which Seller could be subject
         to any liability that is reasonably likely to have a Material Adverse
         Effect.

         4.18 Taxes.

                  4.18.1 Except as set forth in Schedule 4.18, (i) all Tax
         Returns of or with respect to any Tax that are required to be filed on
         or before the Closing Date by or with respect to the Company or any
         affiliated group of corporations of which the Company is or was a
         member at any time prior to and including the Closing Date (a "Seller
         Affiliated Group") have been or will be duly and timely filed, (ii) all
         items of income, gain, loss, deduction and credit or other items
         required to be included in each such Tax Return have been or will be so
         included and all information provided in each such Tax Return is or
         will be true, correct and complete in all material respects, (iii) all
         Taxes which have become or will become due with respect to the period
         covered by each such Tax Return have been or will be timely paid in
         full, (iv) all withholding Tax requirements imposed on or with respect
         to the Company have been or will be satisfied in full, and (v) no
         penalty, interest or other charge is or will become due with respect to
         the late filing of any such Tax Return or late payment of any such Tax.
<PAGE>   12
                  4.18.2 All Tax Returns of, or with respect to the Company or
         any Seller Affiliated Group have been audited by the applicable
         governmental authority, or the applicable statute of limitations has
         expired, for all periods up to and including the periods set forth in
         Schedule 4.18.

                  4.18.3 There is no claim against the Company or any Seller
         Affiliated Group for any Taxes, and no assessment, deficiency or
         adjustment has been asserted or proposed with respect to any Tax Return
         of or with respect to the Company or any Seller Affiliated Group, other
         than those disclosed (and to which are attached true and complete
         copies of all audit or similar reports) in Schedule 4.18.

                  4.18.4 Except as set forth in Schedule 4.18, there is not in
         force any extension of time with respect to the due date for the filing
         of any Tax Return of or with respect to the Company or any Seller
         Affiliated Group or any waiver or agreement for any extension of time
         for the assessment or payment of any Tax of or with respect to the
         Company or any Seller Affiliated Group.

                  4.18.5 Schedule 4.18 contains a true and complete copy of each
         written Tax allocation or sharing agreement and a true and complete
         description of each unwritten Tax allocation or sharing arrangement
         with any Seller Affiliated Group affecting the Company. All such
         agreements shall be terminated prior to the Closing Date and no
         payments are due or will become due by the Company on or after the
         Closing Date pursuant to any such agreement or arrangement.

                  4.18.6 Except as set forth in Schedule 4.18, none of the
         property of the Company is held in an arrangement that could be
         classified as a partnership for Tax purposes, and the Company does not
         own any interest in any controlled foreign corporation (as defined in
         Section 957 of the Code), passive foreign investment company (as
         defined in Section 1296 of the Code) or other entity the income of
         which is required to be included in the income of the Company.

                  4.18.7 Except as set forth in Schedule 4.18, none of the
         property of the Company is subject to a safe-harbor lease (pursuant to
         Section 168(f)(8) of the Internal Revenue Code of 1954 as in effect
         after the Economic Recovery Tax Act of 1981 and before the Tax Reform
         Act of 1986) or is "tax-exempt use property" (within the meaning of
         Section 168(h) of the Code) or "tax-exempt bond financed property"
         (within the meaning of Section 168(g)(5) of the Code).

                  4.18.8 Except as set forth in Schedule 4.18, the Company will
         not be required to include any amount in income for any taxable period
         beginning after the Closing Date as a result of a change in accounting
         method for any taxable period ending on or before the Closing Date or
         pursuant to any agreement with any Tax authority with respect to any
         such taxable period.

                  4.18.9 The Company has not consented to have the provisions of
         Section 341 (f)(2) of the Code apply with respect to a sale of its
         stock.

         4.19 Consents and Approvals. To the best of Seller's knowledge and
belief and except for the applicable requirements of the HSR Act and any matters
set forth on Schedule 4.19 hereto, no other consent, approval, authorization,
declaration, filing or registration with any Governmental Entity or any other
person or entity is required to be made or obtained by Seller or the Company in
connection with the execution, delivery and performance of this Agreement and
the consummation of the transactions contemplated hereby.

         4.20 No Broker's Fees. Seller represents and warrants that neither
Seller nor Company have taken any action that would give any third party a right
to claim a broker's or finder's fee or commission in connection with the
transactions contemplated herein, except for any such fee payable solely by
Seller.

         4.21 Labor and Employment Matters.
<PAGE>   13
                  4.21.1 Except as set forth on Schedule 4.21.1, Company is not
         a party to any contract or collective bargaining agreement with any
         labor organization. Seller has delivered to Purchaser true and correct
         copies of the collective bargaining agreements set forth on Schedule
         4.21.1. To the best knowledge of Seller, other than as set forth on
         Schedule 4.21.1, no organization or representation question is pending
         respecting Company's employees, and no such question has been raised
         within the preceding three years.

                  4.21.2 There is no controversy pending between Company and any
         of its employees or their representatives, except those that would not
         have a Material Adverse Effect on Company. Except as set forth on
         Schedule 4.21.2, to the best knowledge of Seller, there is no basis for
         any claim, grievance, arbitration, negotiation, suit, action or charge
         of or by any employee (or employee representative) of Company, and no
         complaint is pending against Company before the National Labor
         Relations Board or any state or local agency. Company has complied in
         all material respects with all applicable statutes, regulations, orders
         and restrictions of the United States of America, all states and other
         subdivisions thereof, all foreign jurisdictions and all agencies and
         instrumentalities of the foregoing respecting employment and employment
         practices, terms and conditions of employment, and wages and hours
         pertaining to Company's employees.

         4.22 No Other Material Liabilities. To the best knowledge and belief of
         Seller, there are no liabilities or obligations of the Company which
         are not disclosed in this Agreement or the Schedules hereto which would
         have a Material Adverse Effect on the Company.

         4.23 Effective Date of Representations and Warranties. All
         representations and warranties of Seller contained in this Agreement
         are and shall be true and correct in all material respects as of the
         date of this Agreement and as of the Closing Date, provided that any
         such representations and warranties that include a materiality
         qualifier shall be true and correct in all respects as of such dates.


                                    ARTICLE V

                        REPRESENTATIONS AND WARRANTIES OF
                                    PURCHASER

         Purchaser hereby represents and warrants to Seller as follows:

         5.1 Organization of Purchaser. Purchaser is duly organized, validly
existing and in good standing under the laws of the State of Arizona.

         5.2 Authorization. Purchaser has full corporate power and authority to
enter into this Agreement, to consummate the transactions contemplated hereby
and to perform its obligations hereunder. The execution, delivery and
performance of this Agreement and the consummation of the transactions
contemplated hereby by Purchaser have been duly authorized by all requisite
corporate action on the part of Purchaser. When this Agreement has been duly
executed and delivered by Purchaser, it will be a valid and binding obligation
of Purchaser enforceable against it in accordance with its terms.

         5.3 No Conflict or Violation. Neither the execution and delivery of
this Agreement nor the consummation of the transactions contemplated hereby will
result in (i) a violation of or a conflict with any provision of the Certificate
of Incorporation or Bylaws of Purchaser, (ii) a breach of or a default under any
term or provision of any contract, agreement, lease, commitment, license,
franchise, permit, authorization or concession to which Purchaser is a party or
an event which with notice, lapse of time, or both, would result in any such
breach or default, or (iii) a violation by Purchaser of any statute, rule,
regulation, ordinance, code, order, judgment, writ, injunction, decree, or
award, or an event which with notice, lapse of time, or both, would result in
any such violation, except, in each case, for violations, conflicts, breaches or
defaults which in the aggregate would not materially hinder or impair the
consummation of the transactions contemplated by this Agreement.
<PAGE>   14
         5.4 Consents and Approvals. To the best of Purchaser's knowledge and
belief and except for the applicable requirements of the HSR Act and any matters
set forth on Schedule 5.4 hereto, no other consent, approval, authorization,
declaration, filing or registration with any Governmental Entity or any other
person or entity is required to be made or obtained by Purchaser in connection
with the execution, delivery and performance of this Agreement and the
consummation of the transactions contemplated hereby.

         5.5 No Broker's Fees. Purchaser represents and warrants that Purchaser
has not taken any action that would give any third party a right to claim a
broker's or finder's fee or commission in connection with the transactions
contemplated herein, except for any such fee payable solely by Purchaser.

         5.6 Effective Date of Representations and Warranties. All
representations and warranties of Purchaser contained in this Agreement are and
shall be true and correct in all material respects as of the date of this
Agreement and as of the Closing Date, provided that any such representations and
warranties that include a materiality qualifier shall be true and correct in all
respects as of such dates.


                                   ARTICLE VI

                         ACTIONS BY SELLER AND PURCHASER
                              PRIOR TO THE CLOSING

         Seller and Purchaser covenant as follows for the period from the date
of this Agreement through the Closing Date:

         6.1 Maintenance of Company. Except as described on Schedule 6.1 hereto
or as otherwise agreed to in writing by Purchaser, Seller shall and shall cause
the Company to comply with the provisions set forth below:

                  6.1.1 The Company shall conduct its business in the ordinary
         and usual course and in the manner heretofore conducted. However, the
         Company shall coordinate with Purchaser concerning the entering into,
         renewal, extension, exercise of any option, or the expiration or
         termination of any lease for any Company facilities.

                  6.1.2 The Company shall not, except in accordance with past
         practices, (i) grant or agree to grant any bonuses to any employee,
         (ii) grant any general increase in the rates of salaries or
         compensation of its or their employees or any specific increase to any
         employee, including executive officers of the Company, (iii) provide
         for any new pension, retirement or other employment benefits to any of
         its or their employees or any increase in any existing benefits, (iv)
         terminate or amend in any respect or provide for any material increase
         in benefits under any Benefit Plan, (v) enter into any new collective
         bargaining agreement, (vi) hire any new executives, or (vii) extend or
         enter into any new employment agreements.

                  6.1.3 The Company shall not amend its charter or by-laws or
         enter into any merger or consolidation agreement.

                  6.1.4 The Company shall not authorize for issuance, issue,
         sell, deliver or agree or commit to issue, sell or deliver (whether
         through the issuance or granting of options, warrants, commitments,
         subscriptions, rights to purchase or otherwise) any capital stock of
         any class or any other securities or equity equivalents or amend any of
         the terms of any such securities or agreements.

                  6.1.5 The Company shall not sell, assign or dispose of any of
         the Company Assets, or incur or assume any liabilities or enter into
         any sale/leaseback or similar transaction, except for sales and
         dispositions of inventory made, or liabilities incurred, in the
         ordinary course of business
<PAGE>   15
         consistent with past practices.

                  6.1.6 The Company shall not assume, guarantee, endorse or
         otherwise become liable or responsible (whether directly, contingently
         or otherwise) for the obligations of any other person or entity except
         in the ordinary and usual course of business consistent with past
         practice.

                  6.1.7 The Company shall not implement or adopt (i) any change
         in its accounting methods or principles or the application thereof or
         (ii) any material change in their tax methods or principles or the
         application thereof.

                  6.1.8 The Company shall not (i) declare or pay any dividend on
         or make any other distribution in respect of any of its capital stock
         or other ownership interests, except as necessary with respect to
         Seller's retention of the Excluded Assets and Liabilities, (ii) split,
         combine or reclassify any of its capital stock or other ownership
         interests or issue or authorize the issuance of any other securities in
         respect of, in lieu of or in substitution for shares of, its capital
         stock or other ownership interests, (iii) purchase, redeem or otherwise
         acquire any shares of its capital stock or other ownership interests,
         (iv) advance or otherwise loan any funds to Seller or any affiliate of
         the Seller or (v) take any preliminary action with respect to the
         foregoing.

         6.2 Confidentiality. Before either party issues an initial press
release makes any other public announcement or disclosure of this Agreement or
the transactions proposed herein, the parties shall agree on the text of such
press release or disclosure. Thereafter and until the Closing, the parties shall
consult with each other concerning any subsequent public statements.

         6.3 Access to Information. Upon Purchaser's request to a contact person
identified by Seller, Seller shall provide to Purchaser, from time to time,
reasonable information concerning the business, property, books and records of
the Company. All information furnished to Purchaser and its representatives
under this Section 6.3 shall be kept confidential by such persons in accordance
with the Confidentiality Agreement dated July 2, 1999, between the Purchaser and
Seller, as amended from time to time (the "Confidentiality Agreement").

         6.4 HSR Filing.

                  6.4.1 Purchaser and Seller (collectively, the "HSR Parties")
         shall make all premerger notification and report form filings required
         under the HSR Act with respect to the transactions contemplated hereby
         as promptly as reasonably possible following execution and delivery of
         this Agreement. Each of the HSR Parties agrees to use reasonable
         efforts to promptly respond to, and fully address, any formal or
         informal inquiry or request for information by a Governmental Entity
         regarding the transactions contemplated hereby. Each HSR Party will
         keep the other HSR Party apprised of the status of any inquiries made
         by any governmental agency or authority with respect to this Agreement
         or the transactions contemplated hereby.
<PAGE>   16
                  6.4.2 Each of the HSR Parties will furnish one another copies
         of all correspondence, filings or communications (or memoranda setting
         forth the substance thereof (collectively, "HSR Documents")) between
         such HSR Party, or any of its respective representatives, on the one
         hand, and any Governmental Entity, or members of the staff of such
         agency or authority, on the other hand, with respect to this Agreement
         or the transactions contemplated hereby; provided, however, that (i)
         with respect to documents and other materials filed by or on behalf of
         an HSR Party with the Antitrust Division of the Department of Justice,
         the Federal Trade Commission or any state attorneys general that are
         otherwise available for review by the other HSR Parties, copies will
         not be required to be so provided, (ii) the other HSR Parties may
         delete all revenue figures relating to any service not provided or any
         product not manufactured or sold by the other HSR Parties or any of
         their respective subsidiaries (according to such other HSR Party's HSR
         Documents) and (iii) with respect to any HSR Party's Documents (a) that
         contain any information which, in the reasonable judgment of such HSR
         Party's counsel, should not be furnished to such other HSR Party
         because of antitrust considerations or (b) relate to a request for
         additional information pursuant to Section (e)(1) of the HSR Act, the
         obligation of an HSR Party to furnish any such HSR Documents to the
         other HSR Party shall be satisfied by the delivery of such HSR
         Documents on a confidential basis to such other HSR Parties' counsel
         pursuant to an appropriate confidentiality agreement.

                  6.4.3 Notwithstanding the foregoing provisions in this Section
         6.4, nothing contained in this Agreement shall be construed so as to
         require any of the HSR Parties or any of their respective subsidiaries
         or affiliates to sell, license, dispose of or hold separate, or to
         operate in any specified manner, any of their respective assets or
         businesses (or to require any of the HSR Parties or any of their
         respective subsidiaries or affiliates to agree to any of the
         foregoing). The obligations of each HSR Party under this Section 6.4 to
         use reasonable efforts with respect to antitrust matters shall be
         limited to compliance with the reporting provisions of the HSR Act and
         with its obligations under this Section 6.4.

         6.5 Change of Company's Name. On or before the Closing, Seller shall
cause the Company to change its name to any names selected in writing by
Purchaser which do not include a reference to "PACCAR" or to any of the other
trademarks or trade names listed on Schedule 1.12.9.


                                   ARTICLE VII

                        CONDITIONS TO SELLER'S OBLIGATION

         The obligations of Seller to consummate the transactions provided for
herein are subject to the satisfaction of each of the following conditions on or
before the Closing Date:

         7.1 Representations True and Correct. The representations and
warranties of Purchaser set forth in this Agreement shall be true and correct in
all material respects at and as of the Closing Date, provided that any such
representations and warranties that include a materiality qualifier shall be
true and correct in all respects.

         7.2 Performance of Agreements. Purchaser shall have performed all
agreements and covenants required hereby to be performed prior to or at the
Closing Date.

         7.3 Certificates. Purchaser will furnish Seller with such certificates
of Purchaser's officers and others as may be reasonably requested by Seller to
evidence compliance with the conditions set forth in this Article VII.

         7.4 Governmental Approvals. The waiting period (and any extension
thereof) under the HSR Act shall have expired or been terminated. No statute,
rule, regulation or order of any court or administrative agency shall be in
effect which prohibits Seller from consummating the transactions contemplated
hereby and no suit, action, investigation or other proceeding shall have been
instituted or
<PAGE>   17
threatened seeking to restrain or prohibit Purchaser or Seller from consummating
the transactions contemplated hereby.

         7.5 Further Action. All consents, approvals, authorizations, exemptions
and waivers set forth in Schedule 5.4 hereto shall been obtained and be
effective and all other consents, approvals, authorizations, exceptions and
waivers from third persons that shall be required in order to enable Seller to
consummate the transactions contemplated hereby shall have been obtained.

         7.6 Legal Opinion. Seller shall have been furnished an opinion of Lon
B. Novatt, Senior Vice President and General Counsel to Purchaser, that (i) this
Agreement and the transactions contemplated hereby have been authorized by all
necessary corporate action on the part of Purchaser, and (ii) this Agreement is
a valid and binding obligation of the Purchaser enforceable according to its
terms, subject to rules of general application concerning equitable principles
and debtor's rights.


                                  ARTICLE VIII

                      CONDITIONS TO PURCHASER'S OBLIGATIONS

         The obligations of Purchaser to consummate the transactions provided
for herein are subject to the satisfaction, on or prior to the Closing Date, of
each of the following conditions:

         8.1 Representations True and Correct. The representations and
warranties of Seller set forth in this Agreement shall be true and correct in
all material respects at and as of the Closing Date, provided that any such
representations and warranties that include a materiality qualifier shall be
true and correct in all respects.

         8.2 Performance of Agreements. Seller shall have performed all
agreements and covenants required hereby to be performed prior to or at the
Closing Date.

         8.3 Certificates. Seller shall furnish Purchaser with such certificates
of Seller's officers and others as may be reasonably requested by Purchaser to
evidence compliance with the conditions set forth in this Article VIII.

         8.4 Governmental Approvals. The waiting period (and any extension
thereof) under the HSR Act shall have expired or been terminated. No statute,
rule, regulation or order of any court or administrative agency shall be in
effect which prohibits the Purchaser from consummating the transactions
contemplated hereby and no suit, action, investigation or other proceeding shall
have been instituted or threatened seeking to restrain or prohibit Purchaser or
Seller from consummating the transactions contemplated hereby.

         8.5 Further Action. All consents, approvals, authorizations, exemptions
and waivers set forth in Schedule 4.19 hereto shall been obtained and be
effective and all other consents, approvals, authorizations, exceptions and
waivers from third persons that shall be required in order to enable Purchaser
to consummate the transactions contemplated hereby shall have been obtained.

         8.6 Legal Opinion. The Purchaser shall have been furnished an opinion
of G. Glen Morie, Vice President and General Counsel of Seller, that (i) this
Agreement and the transactions contemplated hereby have been authorized by all
necessary action on the part of the Seller, (ii) this Agreement is a valid and
binding obligation of the Seller enforceable according to its terms, subject to
rules of general application concerning equitable principles and debtor's
rights, and (iii) all of the outstanding shares of Company Stock have been duly
authorized and validly issued and are fully paid and nonassessable and free and
clear of any Encumbrances.
<PAGE>   18
                                   ARTICLE IX

                ACTIONS BY SELLER AND PURCHASER AFTER THE CLOSING

         9.1 Transfer of Excluded Assets and Liabilities. Purchaser shall cause
Company to take whatever actions are necessary or useful to transfer to Seller
any portion of the Excluded Assets and Liabilities which may be in or come into
Company's possession at any time after the Closing. Seller shall take whatever
actions are necessary or useful to transfer to Company or Purchaser any portion
of the Company Assets which may be in or come into Seller's possession at any
time after the Closing.

         9.2 Books and Records. Seller and Purchaser agree that so long as any
books, records and files retained by either party relating to the Company's
business and the Company Assets for any period prior to the Closing are
available, each party (at its expense) shall have the right to inspect and to
make copies at any time during business hours for any proper purpose. Neither of
the parties hereto will destroy any of such books, records and files without
first having offered to deliver such books and records to the other party. Each
party agrees that it will cooperate with and make available to the other party
during normal business hours any books, records, information and employees
necessary and useful in connection with (i) any tax inquiry, audit,
investigation or dispute, (ii) any litigation or investigation, (iii) any
environmental investigation or proceeding, or (iv) any other reasonable business
purpose requiring access to such books, records, information or employees. The
party requesting any such books, records, information or employees shall bear
all of the out-of-pocket costs and expenses (including without limitation
attorney's fees, but excluding reimbursement for salaries and employee benefits)
reasonably incurred in connection with providing such books, records,
information or employees.

         9.3 Employee Matters. Except for the Employees listed on Schedule 9.3
attached hereto, Seller shall not employ or offer employment to any of the
Employees for a period of one year after the Closing Date, without the prior
written consent of Purchaser. Any employee who receives an offer from Seller as
permitted herein may decide to continue his employment with Company or to accept
the offer from Seller. Seller shall ensure that any such employee who accepts
the offer of employment from PACCAR will be available to assist Purchaser during
the transition period described in Section 9.11 under the terms of the
Transition Agreement.

         9.4 Environmental Remediation. Seller will remediate any contamination
of the soil or groundwater of the Real Property listed in Schedule 4.16 to the
level necessary to satisfy applicable mandatory federal, state and local
requirements for general retail use. All such remediation efforts shall be
conducted by Seller at Seller's expense and in a reasonable time period after
the Closing, taking into account the cost, urgency and effectiveness of the
remediation efforts and inconvenience to the Company's operations at such
location. Purchaser will cooperate with Seller and allow Seller access to any
affected property in order to remediate any such contamination. Seller shall be
responsible for any fines or penalties or other Damages imposed because of the
contamination listed on Schedule 4.16 or related to the remediation thereof by
Seller.

         9.5 Survival of Representations and Warranties. The several
representations and warranties of the parties to this Agreement shall survive
the Closing Date and shall remain in full force and effect for a period of 6
months following the Closing Date (the "Survival Period"), except that (a) the
representations and warranties set forth in Sections 4.1, 4.2, 4.3, 4.5, 5.1 and
5.2 shall survive the Closing Date without limitation, and (b) in the case of
the representations and warranties provided in Section 4.18, to the extent the
breach thereof results in the Company being liable for Taxes of any person other
than the Company pursuant to Treasury Regulation Section 1.1502-6, the Survival
Period shall extend until 60 days following the expiration of the applicable
statute of limitations. Any claim for a breach of a representation or warranty
must be made by the delivery to the breaching party of a written notice
providing specific details of the alleged breach within the Survival Period. Any
claim for breach of a representation or warranty made during the Survival Period
shall be timely, notwithstanding the fact that such claim may not be resolved
within the Survival Period. All representations and warranties made by the
parties shall not be affected by any investigation heretofore or hereafter made
by or on behalf of any party, except for matters specifically
<PAGE>   19
disclosed in one of the Schedules to this Agreement or to the extent taken into
account in determining the "Net Assets" on the Final Statement of Net Assets.

         9.6 Survival of Covenants and Agreements. All covenants and agreements
contained herein shall survive the Closing without limitation; provided,
however, that such survival shall not operate to expand the indemnification
obligations set forth in Section 9.8.

         9.7 Breach of Environmental Representations and Warranties by Seller.
Subject to the Survival Period limitation contained in Section 9.5, in the event
any representation or warranty made by Seller related to the environmental
condition of the Real Property under Section 4.16 shall be proved to be
incorrect when made, Purchaser's sole remedy shall be to have Seller remediate
any such contamination to the level necessary to satisfy applicable mandatory
federal, state and local requirements for general retail use. All remediation
efforts shall be conducted by Seller at Seller's expense and in a reasonable
time period, taking into account the cost, urgency and effectiveness of the
remediation efforts and inconvenience to the Company's operations at such
location. Purchaser and Company will cooperate with Seller and allow Seller
access to any affected property in order to remediate any such contamination.
Seller shall be responsible for any fines or penalties or other Damages imposed
because of such contamination or related to the remediation thereof by Seller.

         9.8 Indemnification.

                  9.8.1 By Seller. Except as otherwise provided in Section 9.7
         hereof, and subject to the Survival Period limitation contained in
         Section 9.5 and the Threshold Requirement of Section 9.9, Seller shall
         indemnify, defend and hold harmless Purchaser, its affiliates and
         subsidiaries, and its and their respective employees, representatives,
         officers, directors and agents from and against any and all Damages
         (whether or not arising out of third-party claims) incurred in
         connection with or arising out of or resulting from or incident to:

                  (i) any breach of any of Seller's representations or
                  warranties under this Agreement;

                  (ii) any breach of any of Seller's other agreements or
                  obligations under this Agreement; or

                  (iii) any Excluded Assets and Liabilities.

         In computing the amount of Damages under Subsection 9.8.1(i) with
         respect to a breach of a representation or warranty concerning the
         value of any of the Company Assets included in the Final Statement of
         Net Assets, the amount of Damages shall be equal to the amount (if any)
         by which the "Net Assets" as shown on the Final Statement of Net Assets
         exceeds the amount which would have been shown as "Net Assets" on the
         Final Statement of Net Assets, if it had been prepared according to
         Section 3.3 based on the true facts and not in reliance on the
         incorrect representation or warranty.

                  9.8.2 By Purchaser or Company. Subject to the Survival Period
         limitation contained in Section 9.5, Purchaser shall (or shall cause
         Company to) indemnify, defend and hold harmless Seller, its affiliates
         and subsidiaries, and its and their respective employees,
         representatives, officers, directors and agents from and against any
         and all Damages (whether or not arising out of third-party claims)
         incurred in connection with or arising out of or resulting from or
         incident to:

                           (i) any breach of any of Purchaser's representations,
                  warranties or obligations under this Agreement;

                           (ii) any Assumed Liability; or

                           (iii) any obligation, liability, claim or cause of
                  action arising from or relating to the Company or its
                  business, unless such obligation, liability, claim or cause of
                  action
<PAGE>   20
                  arises from or relates to (a) the Excluded Assets and
                  Liabilities, (b) Seller's obligations under Section 9.7
                  hereof, or (c) a breach of Seller's representations,
                  warranties, agreements or obligations which Seller is
                  obligated to indemnify Purchaser for under Section 9.8.1 of
                  this Agreement.

                  9.8.3 Defense of Claims. If any lawsuit or enforcement action
         is filed against any party entitled to the benefit of indemnity
         hereunder, written notice thereof shall be given to the indemnifying
         party as promptly as practicable (and in any event within fifteen (15)
         days after the service of the citation or summons); provided that the
         failure of any indemnified party to give timely notice shall not affect
         the right to indemnification hereunder except to the extent that the
         indemnifying party demonstrates actual prejudice caused by such
         failure. After such notice, the indemnifying party shall be entitled to
         take control of the defense and investigation of such lawsuit or action
         and any appeal arising therefrom and shall pay any resulting judgment
         or settlement, all at its sole cost and expense; provided, however,
         that the indemnified party, at its own cost, may participate in such
         investigation, trial and defense of such lawsuit or action and any
         appeal arising therefrom without affecting the indemnifying party's
         obligations hereunder. If the indemnifying party fails to provide a
         defense to such suit or action, the indemnified party may defend itself
         and compromise or settle the lawsuit or action on any commercially
         reasonable basis, at the full risk and expense of the indemnifying
         party. Notwithstanding the foregoing, (i) the indemnifying party shall
         not settle any lawsuit or action without the prior written consent of
         the indemnified party, which shall not be withheld unreasonably, and
         (ii) the indemnified party may at any time assume control of such
         lawsuit or action if (A) such lawsuit or action involves equitable
         relief against the indemnified party, or (B) such lawsuit or action
         involves an Employee. If the indemnified party assumes the defense of
         such lawsuit or action as provided above, the indemnified party shall
         not settle such lawsuit or action without the prior written consent of
         the indemnifying party, which shall not be withheld unreasonably.

         9.9 Materiality and Threshold Requirement. There shall be no
indemnification under Section 9.8.1 for a breach of any representation or
warranty, unless and until the Damages for all breaches of representations and
warranties by Seller exceed $500,000 in the aggregate (the "Threshold
Requirement"), and once all such Damages exceed the Threshold Requirement,
Seller shall be obligated only for Damages for such breaches of representations
and warranties in the aggregate in excess of the Threshold Requirement. The
Threshold Requirement shall not apply to the following claims:

         (i) indemnification claims under Section 9.8.1(ii);

         (ii) indemnification claims under Section 9.8.1(iii);

         (iii) claims for breach of the representations and warranties provided
         in Section 4.16; and

         (iv) claims for breach of the representations and warranties provided
         in Section 4.18, to the extent the breach thereof results in the
         Company being liable for Taxes of any person other than the Company
         pursuant to Treasury Regulation Section 1.1502-6;

and all such indemnifications shall be without limitation.

         9.10 Waiver of Contribution.

                  9.10.1 Seller acknowledges and agrees that it shall not seek
         or receive indemnification or contribution from the Company with
         respect to any claim for indemnification properly made against Seller
         under Section 9.8.1.
<PAGE>   21
                  9.10.2 Purchaser (on its own behalf and on behalf of the
         Company) acknowledges and agrees that neither Purchaser nor Company
         shall seek or receive indemnification or contribution from Seller with
         respect to any claim for indemnification properly made against
         Purchaser (or the Company) under Section 9.8.2.

         9.11 Transition Period. During a transition period and pursuant to the
terms of the Transition Agreement substantially in the form attached hereto as
Exhibit A, Seller will provide any distribution and administrative services,
including without limitation fixed asset management, payroll and benefits,
worker's compensation, computing services, and credit, tax and legal services,
reasonably requested by Purchaser, at charges not to exceed the fair market
value of such services. The Transition Agreement shall provide that Purchaser
shall reimburse Seller for all costs and expenses incurred and indemnify Seller
from any claims and causes of action that may arise in connection with the
services to be provided under this section.

         9.12 Letters of Credit. Seller has established various LC's listed in
Schedule 1.12.6 for the benefit of the Company or the benefit of Seller and its
affiliates (including the Company) in connection with certain leases and
workers' compensation programs. Seller will terminate these LC's (or terminate
coverage of the Company under such LC's) effective the Closing Date. Purchaser
understands and agrees that it will replace these LC's or make other
arrangements in order to comply with the requirements of these leases and
workers' compensation laws. Purchaser will indemnify Seller from any and all
claims, costs and expenses paid by Seller after the Closing in connection with
these matters, until Purchaser has established replacement programs, insurance
policies or LC's.

         9.13 Covenants Not to Compete. Seller agrees that, for a period of two
(2) years following the Closing Date, Seller and its affiliates shall not
directly or indirectly compete in the business of the Company. The parties
acknowledge and agree that any breach of this Section 9.13 will result in
irreparable harm to Purchaser and that a remedy at law will be inadequate.
Purchaser shall be entitled to specific performance and injunctive and other
equitable relief in case of any such breach or attempted breach. The parties
acknowledge that this covenant not to compete is being provided as an inducement
to Purchaser to engage in the transactions set forth herein and that this
Section 9.13 contains reasonable limitations as to time, geographical area and
scope of activity to be restrained that do not impose a greater restraint than
is necessary to protect the goodwill or other business interest of Purchaser. In
the event that the provisions of this Section 9.13 should ever be deemed to
exceed the time or geographic limitations permitted by applicable laws, then
such provision shall be reformed to the maximum time or geographic limitations
permitted by applicable law.

         9.14 Taxes. All sales, use, excise, or other transfer taxes, if any,
which are imposed on the transfer of the Company Stock or are imposed on the
Company because of the transfer of the Company Stock as set forth herein shall
be paid by the Purchaser.

         9.15 Straddle Period Tax Provisions.

                  9.15.1 Purchaser and Seller agree to file all Tax Returns for
         the period including the Closing Date on the basis that (i) the Closing
         occurred as of 5:00 p.m. on the Closing Date, and (ii) the relevant
         taxable period ended as of the close of business on the Closing Date,
         unless the relevant taxing authority will not accept a return, report
         or form filed on that basis. In the case of any Tax period including,
         but not ending on, the Closing Date, the income of the Company will be
         apportioned to the period up to and including the Closing Date and the
         period after the Closing Date by closing the books of the Company as of
         the end of the Closing Date.

                  9.15.2 The Seller will include the income of the Company for
         the period including or ending on the Closing Date on the Seller's
         consolidated federal, and
<PAGE>   22
         any applicable state combined or other group income Tax Returns for all
         periods that include or end on the Closing Date and will pay any
         federal or applicable state income Taxes attributable to such income.
         The Seller will allow the Company to review and comment upon such Tax
         Returns (including any amended Returns) to the extent that they relate
         to the Company. The Seller will take no positions on such Tax Returns
         that relate to the Company that would adversely affect the Company
         after the Closing Date, unless such position would be reasonable in the
         case of a person that owned the Company both before and after the
         Closing Date. The income of the Company will be apportioned to the
         period up to and including the Closing Date and the period after the
         Closing Date by closing the books of the Company as of the end of the
         Closing Date.

                  9.15.3 The Seller will be responsible for the preparation and
         filing of all Tax Returns for the Company for all tax periods ending on
         or before the Closing Date. The Purchaser will be responsible for the
         preparation and filing of all Tax Returns for the Company for all tax
         periods after the Closing Date, other than for Taxes with respect to
         periods for which the consolidated, unitary and combined Tax Returns of
         the Seller will include the operations of the Company.

                  9.15.4 Seller, the Company and Purchaser shall reasonably
         cooperate, and shall cause their respective affiliates, officers,
         employees, agents, auditors and representatives reasonably to
         cooperate, in preparing and filing all returns, reports and forms
         relating to taxes (including amended returns and claims for refund),
         including maintaining and making available to each other all records
         necessary in connection with taxes and in resolving all disputes and
         audits with respect to all taxable periods relating to taxes. Purchaser
         and Seller recognize that Seller and its affiliates will need access,
         from time to time, after the Closing Date, to certain accounting and
         tax records and information held by the Company to the extend such
         records and information pertain to events occurring prior to the
         Closing Date; therefore, Purchaser agrees, and agrees to cause the
         Company and the Subsidiary, to (i) use their best efforts to properly
         retain and maintain such records until such time as Seller agrees that
         such retention and maintenance is no longer necessary, and (ii) allow
         Seller and its agents and representatives (and agents or
         representatives of any of its affiliates), at time and dates mutually
         acceptable to the parties, to inspect, review and make copies of such
         records as Seller may deem necessary or appropriate from time to time,
         such activities to be conducted during normal business hours and at
         Seller's expense.

         9.16 Section 338(h)(10) Election. At the Purchaser's election, the
Seller shall join with the Purchaser in making a joint election pursuant to
Section 338(h)(10) of the Code (and any similar provision of state, local or
applicable foreign law) with respect to the purchase and sale of the stock of
the Company. The Seller shall cooperate with the Purchaser in the completion and
timely filing of such election in accordance with the provisions of Treasury
Regulation Section 1.338(h)(10)-1 (or any similar provision of state, local or
applicable foreign law) or any successor provision. With respect to such
election(s), the Seller and the Purchaser agree that the Purchase Price for the
stock of Company will be allocated among the assets of the Company in accordance
with the fair market values thereof and pursuant to an allocation to be provided
to the Seller by the Purchaser and reasonably acceptable to Seller. The Seller
and the Purchaser agree that all Tax Returns (including amended Tax Returns and
claims for refund) will be filed in a manner consistent with such allocation.

         9.17 Further Assurances and Cooperation. On and after the Closing Date,
Seller and Purchaser will take all appropriate actions and execute any
documents, instruments or conveyances of any kind which may be reasonably
necessary or advisable to carry out or to assist the other party to carry out
any of its or their obligations under the provisions of this Agreement.

         9.18 Financial Statements. Within forty-five (45) days following the
Closing Date, Seller will provide to Purchaser audited financial statements of
the Company, prepared in accordance with Rule 3-05 of Regulation S-X under the
Securities Exchange Act of 1934, for the Company's latest fiscal year
<PAGE>   23
and similarly prepared unaudited statements for the period following such fiscal
year end through the last fiscal quarter of the Company ended prior to the
Closing Date.


                                    ARTICLE X

                                  MISCELLANEOUS

         10.1 Termination. If any condition precedent to Seller's obligations
hereunder is not satisfied and such condition is not waived by Seller at or
prior to the Closing Date, or if any condition precedent to Purchaser's
obligations hereunder is not satisfied and such condition is not waived by
Purchaser at or prior to the Closing Date, Seller or Purchaser, as the case may
be, may terminate this Agreement at its option by notice to the other party,
unless the party intending to give such notice is in default under its
obligations hereunder. If the approval conditions under Sections 7.4 and 8.4
hereof have not been satisfied by December 31, 1999, either party may terminate
this Agreement by giving 10 days written notice to the other party, and this
Agreement shall automatically terminate at the end of the notice period unless
the conditions have been satisfied by then. In the event of the termination of
this Agreement by either party as above provided, neither party shall have any
liability hereunder of any nature whatsoever (other than pursuant to Sections
6.2 and 10.2 hereof) to the other party and except that no such termination
shall relieve any party from any liability for any prior breach of this
Agreement. In the event that a condition precedent to its obligations is not
satisfied, nothing contained herein shall be deemed to require any party to
terminate this Agreement, rather than to waive such condition precedent and
proceed with the Closing.

         10.2 Confidential Information. In connection with the negotiation of
this Agreement and the preparation for the consummation of the transactions
contemplated herein, each party has had access to confidential information
relating to the other party. Each party agrees to restrict such information
(including knowledge of this Agreement and the transactions contemplated herein)
to those and only those employees, attorneys, accountants, advisors and
consultants who need to know such information. Each party shall treat all such
information as confidential, shall preserve the confidentiality thereof and
shall not duplicate or use such information except in connection with the
transactions contemplated hereby. In the event of the termination of this
Agreement for any reason whatsoever, each party shall return to the other all
documents, work papers and other material (including all copies thereof)
obtained in connection with the transactions contemplated hereby and will use
all reasonable efforts, including instructing its employees who have had access
to such information, to keep confidential and not to use any such information,
unless such information is now or is hereafter disclosed, through no act or
omission of such party, in any manner making it available to the general public.

         10.3 Assignment. Neither this Agreement nor any of the rights and
obligations hereunder may be assigned by either party without the prior written
consent of the other. The foregoing notwithstanding, the Purchaser may assign
all of its rights under this Agreement after the Closing, but such assignment
shall not release Purchaser from its obligations under this Agreement.

         10.4 Notices. Unless otherwise provided herein, any notice, request,
instruction or other document to be given hereunder by either party to the other
shall be in writing and delivered personally, by express courier, by facsimile
(with confirmed "OK" transmission status) or mailed by certified mail, postage
prepaid, return receipt requested, as follows:

                  If to Seller, addressed to:

                           PACCAR Inc
                           P.O. Box 1518
                           Bellevue, WA 98009
                           Attention:   M. A. Tembreull, Vice Chairman
                           Facsimile:  (425) 468-8230
                           Telephone: (425) 468-7366
<PAGE>   24
                  With copies to:

                           PACCAR Inc
                           P.O. Box 1518
                           Bellevue, WA 98009
                           Attention:  G. Glen Morie, Vice President and General
                                       Counsel
                           Facsimile: (425) 468-8228
                           Telephone: (425) 468-7499

                  If to Purchaser, addressed to:

                           CSK AUTO
                           645 E Missouri Avenue, Suite 400
                           Phoenix, AZ 85012-1373
                           Attention: Jim Bazlen, President
                           Facsimile:  (602) 234-1713
                                                      TELEPHONE: (602) 631- 7005

                  With copies to:

                           CSK AUTO
                           645 E Missouri Avenue, Suite 400
                           Phoenix, AZ 85012-1373
                           Attention:  Lon B. Novatt, Senior Vice President &
                                       General Counsel
                           Facsimile:  (602) 264-0495
                           Telephone:  (602) 631-7358

or such other place and with such other copies as any party may designate by
written notice to the others. Notices delivered personally or sent by express
courier shall be effective when delivered. Notices sent by Facsimile (with
confirmed "OK" transmission status) shall be effective when sent, and Notices
sent by certified mail shall be effective on the date receipt is acknowledged.

         10.5 Choice of Law and Interpretation. This Agreement shall be
construed and interpreted and the rights of the parties determined in accordance
with the laws of the State of Washington. Both parties acknowledge that this
Agreement has been negotiated and prepared with the participation of legal
counsel for both parties, and they agree that the Agreement shall be interpreted
and construed without reference to either party as being the author or preparer
of the Agreement.

         10.6 Entire Agreement; Amendments and Waivers. This Agreement, together
with all Exhibits and Schedules hereto, constitutes the entire agreement among
the parties pertaining to the subject matter hereof and supersedes all prior
agreements, understandings, negotiations and discussions of the parties, whether
oral or written. No supplement, modification or waiver of this Agreement shall
be binding unless it is set forth in writing and signed by the party to be bound
thereby. No waiver of any of the provisions of this Agreement shall be deemed to
or shall constitute a waiver of any other provision hereof, and the waiver of
any default shall not be deemed to be a waiver of any other or subsequent
default.

         10.7 Multiple Counterparts. This Agreement may be executed in one or
more counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

         10.8 Expenses. Each party hereto shall pay its own expenses incident to
this Agreement and to any action taken by such party in performing its
obligations under this Agreement.

         10.9 Invalidity. Whenever possible, each provision of this Agreement
shall be interpreted in such a manner as to be effective and valid under
applicable law. If any provision of this Agreement shall be prohibited by or
invalid, illegal or unenforceable under applicable law, such provision shall be
ineffective
<PAGE>   25
only to the extent of such prohibition or invalidity, illegality or
unenforceability without affecting the remaining portion of that provision or
the other provisions of this Agreement.

         10.10 Headings. The headings of the Articles and Sections are not
intended to be a part of this Agreement.

         10.11 Resolution of Disputes. In the event of any dispute concerning
this Agreement, the parties shall attempt in good faith to settle the dispute
among themselves, and if this is not successful, they shall seek alternative
methods to resolve the dispute in a cost effective manner before commencing
litigation.

         10.12 Legal Fees. In the event of any arbitration or litigation
concerning the enforcement of this Agreement, the prevailing party shall be
entitled to recover its costs and expenses, including reasonable attorneys'
fees.

         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed by their respective officers, thereunto duly authorized, in
multiple originals, all as of the day and year first above written.

SELLER:  PACCAR Inc                          PURCHASER: CSK Auto, Inc.

By: /s/ G.Glen Morie                         By: /s/ L. Novatt

Title:  Vice President                       Title: Senior Vice President
<PAGE>   26
                                LIST OF SCHEDULES

1.6.1             Real Property

1.6.5             Contracts with Obligations in Excess of $ 50,000.

1.6.6             Trademarks

1.6.8             Store Opening Cash Balances

1.12.1            Excluded Real Property

1.12.3(a)         Excluded Bank and Trust Accounts

1.12.3(b)         Excluded Cash

1.12.6            Excluded Letters of Credit

1.12.9            Excluded Trademarks, Etc.

1.12.10           Excluded Equipment, Etc.

1.12.11           Excluded Company and Seller Benefit Plans

1.12.12           Excluded Settlement Proceeds

1.17              Items Excluded from Adjustment of Net Assets

1.18(a)           Statement of Net Assets

1.18(b)           Statement of Reserves

4.6.4             Statement of Operating Income

4.7               Encumbrances on Company Assets

4.8               Encumbrances on Real Property

4.9               Exceptions to Certain Agreements

4.10              Exceptions to Contract Representations

4.12              Exceptions to Accounts Receivable Representations

4.13              Litigation and Proceedings

4.14              Exceptions to Licenses, Permits and Authorizations
                  Representations

4.15              Exceptions to Compliance Representations

4.16              Exceptions to Environmental Disclosures

4.17              Pension and Benefit Plans

                  4.17.1            Benefit Plans
<PAGE>   27
                  4.17.2            Tax Qualification Exceptions

                  4.17.3            ERISA   Exceptions

                  4.17.4            VEBA

                  4.17.5            Change of Control

                  4.17.6            Post Retiree Medical Coverage

                  4.17.7            Prohibited Transactions

                  4.17.8            Employee Welfare Benefit Plans

4.18              Taxes and Tax Returns

                  4.18.1            Tax Returns Filed

                  4.18.2            Years Audited

                  4.18.3            Tax Assessments

                  4.18.4            Tax Extensions

                  4.18.5            Tax Allocation Agreements

                  4.18.6            Tax Partnerships

                  4.18.7            Safe Harbor Leases

                  4.18.8            Agreements with Tax Authorities

                  4.18.9            Section 341

4.19              Seller's Required Consents and Approvals

4.21.1            Collective Bargaining Agreements

4.21.2            Employee Claims

5.4               Purchaser's Required Consents and Approvals

6.1               Exceptions to Ordinary Course Transactions

9.3               Employees to Whom Seller May Make Offer of Employment