Document:

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                                                                 EXHIBIT 4(e)(7)

                   SIXTH AMENDMENT TO NOTE PURCHASE AGREEMENT
                                       RE:
                          CREDIT ACCEPTANCE CORPORATION
                           SECOND AMENDED AND RESTATED
                     9.27% SENIOR NOTES DUE OCTOBER 1, 2001

                                                       Dated as of March 8, 2001

To the Noteholders listed on Annex I hereto

Ladies and Gentlemen:

         Credit Acceptance Corporation, a Michigan corporation (together with
its successors and assigns, the "Company"), hereby agrees with you as follows:

SECTION 1.        INTRODUCTORY MATTERS.

         1.1      DESCRIPTION OF OUTSTANDING NOTES. The Company currently has
outstanding its Second Amended and Restated 9.27% Senior Notes due October 1,
2001 (collectively, the "Notes") which it issued pursuant to the separate Note
Purchase Agreements, each dated as of March 25, 1997 (collectively, as amended
by the First Amendment to Note Purchase Agreement, dated as of December 12,
1997, the Second Amendment to Note Purchase Agreement, dated as of July 1, 1998,
the Third Amendment to Note Purchase Agreement, dated as of April 13, 1999, the
Fourth Amendment, dated as of December 1, 1999, and the Fifth Amendment, dated
as of April 27, 2000, the "Agreement"), entered into by the Company with each of
the original holders of the Notes listed on Annex 1 thereto, respectively. Terms
used herein but not otherwise defined herein shall have the meanings assigned
thereto in the Agreement, as amended hereby.

         1.2      PURPOSE OF AMENDMENT. The Company and you desire to amend the
Agreement as set forth in Section 2 hereof.

SECTION 2.        AMENDMENT TO THE AGREEMENT.

         Pursuant to Section 10.5 of the Agreement, the Company hereby agrees
with you that the Agreement shall be amended by this Sixth Amendment to Note
Purchase Agreement (this "Sixth Amendment") in the following respects:

         2.1      SECTION 6.1. (a) Sections 6.1(a)(i), 6.1(b)(i) and 6.1(c) are
each amended by adding the following at the end thereof, immediately following
the word "GAAP" (prior to the ending punctuation):

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                  , other than Debt represented by Intercompany Loans incurred
                  by the English Special Purpose Subsidiary pursuant to the UK
                  Restructuring

                  (b) Section 6.1(d) is hereby amended by adding the following
at the end thereof (before the "."):

                  or (C) on or after June 13, 2000, thirty-five percent (35%) of
                  Consolidated Tangible Net Worth

         2.2      SECTION 6.6. Section 6.6(a)(i) is amended and restated in its
entirety as follows:

                           (i)      (A) Liens securing Property taxes,
                  assessments or governmental charges or levies or the claims or
                  demands of materialmen, mechanics, carriers, warehousemen,
                  vendors, landlords and other like Persons, provided that the
                  payment thereof is not at the time required by Section 6.12,
                  (B) any Lien encumbering Securitization Property which is the
                  subject of a Transfer pursuant to a Permitted Securitization,
                  (C) any Lien granted in favor of the "Collateral Agent" (as
                  defined in the Intercreditor Agreement) for the benefit of the
                  Banks, the holders of Notes and "Future Debt Holders" (as
                  defined in the Intercreditor Agreement) and subject to the
                  Intercreditor Agreement, and (D) Liens encumbering assets
                  owned by CAC UK securing Debt incurred by Subsidiaries
                  organized outside the United States if, in the case of this
                  clause (D), immediately before and after the incurrence of any
                  such Lien, and after giving effect thereto and to any
                  concurrent transactions, no Default or Event of Default would
                  exist;

         2.3      SECTION 6.7. Section 6.7(a) is amended by replacing the "." at
the end thereof with "; and" and by adding the following at the end thereof:

                           (v)      Transfers made in accordance with the terms
                  of the UK Restructuring if, immediately before and after the
                  consummation of such Transfer, and after giving effect thereto
                  and to any concurrent transactions, no Default or Event of
                  Default would exist.

         2.4      SECTION 6.8(a). (a) Clause (i) of Section 6.8(a) is hereby
amended in its entirety as follows:

                           (i)      (A) Transfers from a Restricted Subsidiary
to the Company or to a Wholly-Owned Restricted Subsidiary; and

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                                    (B) Transfers from an Unrestricted
                  Subsidiary to the Company or to a Wholly-Owned Restricted
                  Subsidiary if, immediately before and after the consummation
                  of such Transfer, and after giving effect thereto and to any
                  concurrent transactions, no Default or Event of Default would
                  exist.

                  (b)      Clause (v) of Section 6.8(a) is hereby amended and
restated in its entirety as follows:

                           (v)      any Transfer made pursuant to the Montana
                  Disposition (including without limitation the transfer by the
                  Company of its intellectual property rights to the name
                  Tele-Track, Inc.), the Arlington Disposition or the UK
                  Restructuring if, immediately before and after the
                  consummation of such Transfer, and after giving effect thereto
                  and to any concurrent transactions, no Default or Event of
                  Default would exist; and

         2.5      SECTION 6.8(c). Section 6.8(c) is hereby amended and restated
in its entirety as follows:

                           (c)      ACCOUNTS RECEIVABLE AND LEASES.
                  Notwithstanding the provisions of Section 6.8(a), except to
                  the Company or a Wholly- Owned Restricted Subsidiary pursuant
                  to Section 6.8(a)(i) or to Comerica Bank in its capacity as
                  "Collateral Agent" under the Intercreditor Agreement, or
                  pursuant to or in connection with a Permitted Securitization,
                  the Montana Disposition, the Arlington Disposition or the UK
                  Restructuring, neither the Company nor any Restricted
                  Subsidiary will Transfer, or reallocate from the Non-Specified
                  Interest to a Specified Interest, any accounts receivable,
                  leases or other financial assets if the sum of

                           (i) the face value of the accounts receivable, leases
                  or other financial assets proposed to be Transferred, plus

                           (ii) the face value of the accounts receivable,
                  leases or other financial assets Transferred by the Company
                  and all Restricted Subsidiaries during the then current fiscal
                  year of the Company (other than pursuant to the UK
                  Restructuring),

                  would exceed five percent (5%) of the face value of the
                  accounts receivable, leases and other financial assets of the
                  Company and the Restricted Subsidiaries determined on a
                  consolidated basis as at the

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                  end of the most recently ended fiscal year of Company prior to
                  giving effect to any such Transfer.

         2.6      SECTION 6.10.  Section 6.10 is amended and restated in its
entirety as follows:

                           6.10     TRANSACTIONS WITH AFFILIATES. The Company
                  will not, and will not permit any Restricted Subsidiary to,
                  enter into any transaction, including, without limitation, the
                  purchase, sale or exchange of Property or the rendering of any
                  service, with any Affiliate, except (a) a Permitted
                  Securitization, (b) transactions in accordance with the terms
                  of the UK Restructuring, or (c) in the ordinary course of and
                  pursuant to the reasonable requirements of the Company's or
                  such Restricted Subsidiary's business and upon fair and
                  reasonable terms no less favorable to the Company or such
                  Restricted Subsidiary than would obtain in a comparable
                  arm's-length transaction with a Person not an Affiliate.

         2.7      SECTION 6.22.     Section 6.22 is added to read as follows:

                           6.22     AMENDMENTS TO TITLING SUBSIDIARY AGREEMENTS.
                  The Company will not, and will not permit the Titling
                  Subsidiary to, amend, modify or otherwise alter (or permit to
                  be amended, modified or altered) in any material respect
                  adverse to the Holders, any of the Titling Subsidiary
                  Agreements or any other documents or instruments relating to
                  the establishment or operation of the Titling Subsidiary. For
                  purposes of such documents or instruments, any amendments to
                  or changes in the provisions relating to the creation or
                  transfer of Specified Interests and the allocation or
                  reallocation of financial assets or other property thereto,
                  and any amendment, modification, resignation or removal
                  whereby the Company shall cease to be the founding member of
                  or otherwise cease to control the Titling Subsidiary or cease
                  to be the administrative agent under the Titling Subsidiary
                  Agreements shall (without reducing the scope of this Section
                  6.22) be deemed to be materially adverse to the Holders.

         2.8      SECTION 6.23.  Section 6.23 is added to read as follows:

                           6.23     CHANGES TO COLLATERAL ARRANGEMENTS.

                                    (a)      Prior to the transfer to or
                  creation in the name of the Titling Subsidiary of any Leased
                  Vehicles or Leases, the Company shall execute and deliver
                  additional agreements (or an

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                  amendment to the Security Agreement, dated as of December 15,
                  1998, executed and delivered by the Company in favor of
                  Comerica Bank, as agent under the Intercreditor Agreement)
                  consisting of a security agreement and pledge encumbering the
                  Company's entire Non-Specified Interest and any related
                  documents or instruments necessary to encumber and/or perfect
                  a security interest in such collateral, all as determined by
                  and in form and substance satisfactory to the "Collateral
                  Agent" and the "Majority Benefited Parties" under the
                  Intercreditor Agreement, in their reasonable discretion.

                                    (b)      Before conducting the UK
                  Restructuring, the Company shall grant a perfected first
                  priority security interest, lien and charge to the "Collateral
                  Agent" under the Intercreditor Agreement in not less than 65%
                  of the aggregate partnership interests of the Scottish
                  Partnership, as security for the indebtedness owed to the
                  parties to the Intercreditor Agreement, on substantially the
                  terms of that certain Deed of Charge dated as of December 17,
                  1998 and executed by Company in favor of the Collateral Agent
                  (subject to local law variations) and otherwise satisfactory
                  in form and substance to the "Collateral Agent" and the
                  "Majority Benefited Parties" under the Intercreditor
                  Agreement, in their reasonable discretion, provided that,
                  concurrently therewith, Collateral Agent shall have released
                  and discharged (or caused to be released and discharged) such
                  Deed of Charge.

         2.9      SECTION 6.24.  Section 6.24 is added to read as follows:

                           6.24     SPECIAL LEASING COVENANTS. Except for Leases
                  with respect to motor vehicles located outside the United
                  States of America and its territories and possessions (which
                  shall be originated by the Company or a Subsidiary, in its own
                  name or using an assumed name), (a) originate and hold Leases
                  other than (x) in the Company's own name or by the Company,
                  but under the assumed name "CAC Auto Leasing" or "AutoNet
                  Finance.com", (y) in the name of AutoNet Finance Company.com,
                  Inc. or CAC Leasing, Inc. to the extent applicable state law
                  prohibits the Company from originating Leases in such state
                  using an assumed name, or (z) in the name of the Titling
                  Subsidiary; and (b) except in connection with a Permitted
                  Securitization, allocate or reallocate Leases, Leased Vehicles
                  or other financial assets to a Specified Interest.

         2.10     SECTION 7.1(j). Clause (2) of Section 7.1(j) is hereby amended
and restated in its entirety as follows:

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                           (2)      promptly upon the request of the Required
                  Holders from time to time (but no more often than
                  semi-annually), a "static pool analysis" which analyzes the
                  performance of any Installment Contracts or Leases
                  transferred, encumbered, reallocated from the Non-Specified
                  Interest to a Specified Interest or otherwise disposed of
                  pursuant to a Permitted Securitization comparable to the
                  static pool analysis required to be delivered pursuant to
                  clause (1) of this Section 7.1(j); and

         2.11     SECTION 8.1(k). Paragraph (k) of Section 8.1 is hereby amended
and restated in its entirety as follows:

                           (k)      SECURITIZATIONS - with respect to the
                  Securitization Documents, the occurrence (beyond any
                  applicable period of grace or cure) of any "servicer event of
                  default" thereunder or the occurrence of any other default
                  (beyond any applicable period of grace or cure) by the Company
                  or any of its Subsidiaries, including any Special Purpose
                  Subsidiary, under the Securitization Documents which can be
                  reasonably expected to result in recourse liability against
                  the Company or any of its Restricted Subsidiaries in an
                  aggregate amount exceeding $2,000,000 or, with respect to the
                  Titling Subsidiary Agreements, the occurrence (beyond any
                  applicable period of grace or cure) of any "administrative
                  agent event of default" thereunder relating to or otherwise
                  enforceable by the holder of a Specified Interest.

         2.12     SECTION 9.1.

                  (a)      The definition of "Cleanup Call" in Section 9.1 is
hereby amended and restated in its entirety as follows:

                  CLEANUP CALL(S) -- means

                           (a) in the case of an optional cleanup call, a
                  cleanup call to be exercised at the option of the Company, the
                  Titling Subsidiary or a Special Purpose Subsidiary under the
                  terms of the applicable Permitted Securitization (provided
                  that, both before and after giving effect thereto, no Default
                  or Event of Default has occurred and is continuing when such
                  option is exercised), in an amount not in excess of (i)
                  Fifteen Percent (15%) of the initial amount received by the
                  Company, the Titling Subsidiary or the Special Purpose
                  Subsidiary pursuant to such Permitted Securitization (before
                  fees and other

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                  deductions), it being understood that, for purposes of the
                  calculation under this clause (a)(i) of this definition, each
                  tranche of a multi-tranche Permitted Securitization shall be
                  considered a separate Permitted Securitization or (ii) in the
                  case of any Securitization Transaction structured on a
                  revolving basis, Fifteen Percent (15%) of the maximum
                  aggregate availability at any time to the Company, the Titling
                  Subsidiary or a Special Purpose Subsidiary, each such optional
                  cleanup call to be accompanied (x) by the repurchase of or
                  release of encumbrances on Advances, Leased Vehicles,
                  Installment Contracts (whether assigned outright or related to
                  Advances) or Leases (whether assigned outright or related to
                  Leased Vehicles), as the case may be, previously transferred
                  or encumbered pursuant to such Permitted Securitization in an
                  amount equal to at least the amount of such cleanup call, or
                  (y) if such Leased Vehicles or Leases are held by the Titling
                  Subsidiary, by the reallocation of such Leases and Leased
                  Vehicles from the applicable Specified Interest to the
                  Non-Specified Interest in an amount equal to at least the
                  amount of such cleanup call, and

                           (b) in the case of a mandatory cleanup call, a
                  mandatory cleanup call to be exercised at the option of the
                  investors under the terms of the applicable Permitted
                  Securitization(s), in an amount not in excess of (i) Two and
                  One-Half Percent (2 1/2%) of the aggregate amount received by
                  the Company, the Titling Subsidiary or a Special Purpose
                  Subsidiary pursuant to the Permitted Securitization to which
                  such mandatory cleanup call relates (before fees and other
                  deductions), it being understood that, for purposes of the
                  calculation under this clause (b)(i) of this definition, all
                  tranches of a multi-tranche Permitted Securitization shall be
                  together be considered one Permitted Securitization, or (ii)
                  in the case of any Securitization Transaction structured on a
                  revolving basis, Two and One-Half Percent (2 1/2%) of the
                  maximum aggregate availability at any time to the Company, the
                  Titling Subsidiary or a Special Purpose Subsidiary, each such
                  mandatory cleanup call to be accompanied (x) by the repurchase
                  of or release of encumbrances on Advances, Leased Vehicles,
                  Installment Contracts (whether assigned outright or related to
                  Advances) or Leases (whether assigned outright or related to
                  Leased Vehicles), as the case may be, previously transferred
                  or encumbered pursuant to such Permitted Securitization in an
                  amount equal to at least the lesser of (A) the amount of such
                  cleanup call or (B) the book value at the time of such cleanup
                  call of the Advances, Leased Vehicles, Installment Contracts
                  or Leases previously transferred or encumbered pursuant to
                  such Permitted Securitization,

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                  or (y) if such Leased Vehicles or Leases are held by the
                  Titling Subsidiary, by the reallocation of such Leases and
                  Leased Vehicles from the applicable Specified Interest to the
                  Non-Specified Interest in an amount equal to at least the
                  lesser of (A) the amount of such cleanup call or (B) the book
                  value at the time of such cleanup call of the Leased Vehicles
                  and Leases currently held in such Specified Interest.

                  (b)      The last sentence of the definition of "Debt" is
hereby amended and restated in its entirety as follows:

                  Except as provided in Sections 6.1(a)(i), 6.1(b)(i) and
                  6.1(c), neither Debt of any Special Purpose Subsidiary which
                  is an Unrestricted Subsidiary incurred pursuant to a Permitted
                  Securitization (whether or not such Debt is reflected on the
                  consolidated balance sheet of the Company and its Restricted
                  Subsidiaries prepared in accordance with GAAP) nor dealer
                  holdbacks shall be considered Debt of the Company or any
                  Restricted Subsidiary.

                  (c)      The definition of "English Special Purpose
Subsidiary" is hereby added to Section 9.1 to read as follows:

                           ENGLISH SPECIAL PURPOSE SUBSIDIARY - means a Special
                  Purpose Subsidiary organized by the Company, as part of the UK
                  Restructuring, under the laws of England.

                  (d)      The definition of "Equity Offering" in Section 9.1 is
hereby amended by adding the following at the end thereof (before the "."):

                  , and other than the creation or disposition of any interest
                  in the Titling Subsidiary

                  (e)      The definition of "Intercompany Loans" is hereby
added to Section 9.1 to read as follows:

                           INTERCOMPANY LOANS - means any loan or advance in the
                  nature of a loan by the Company to any Subsidiary or by any
                  Subsidiary to any other Subsidiary or to the Company.

                  (f)      The definition of "Intercompany Loans, Advances and
Investments" is hereby added to Section 9.1 to read as follows:

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                           INTERCOMPANY LOANS, ADVANCES AND INVESTMENTS - means
                  any Intercompany Loan and any other advance or Investment by
                  the Company to a Subsidiary or by any Subsidiary to the
                  Company or any other Subsidiary.

                  (g)      The definition of "Leased Vehicles" in Section 9.1 is
hereby amended and restated in its entirety as follows:

                           LEASED VEHICLES - means, as of any applicable date of
                  determination, the dollar amount of advances in respect of
                  Leases, as such amount would appear in the footnotes to the
                  financial statements of the Company and its Restricted
                  Subsidiaries prepared in accordance with GAAP or, if
                  specifically identified, elsewhere in such financial
                  statements, net of depreciation on the motor vehicles which
                  are covered by Leases with respect to which such Leased
                  Vehicles are attributable (and if such amount is not shown net
                  of such reserves, then net of any reserves established by the
                  Company as an allowance for credit losses related to such
                  advances not expected to be recovered), provided that Leased
                  Vehicles shall not include (a) the amount of any such advances
                  attributable to any Leases transferred or encumbered or
                  reallocated from the Non-Specified Interest to a Specified
                  Interest pursuant to a Permitted Securitization (whether or
                  not attributable to the Company under GAAP) unless and until
                  such advances (and the related Leases) are either reassigned
                  to the Company or a Restricted Subsidiary (other than the
                  Titling Subsidiary) or such encumbrances are discharged, or
                  such advances (and the related Leases and vehicles) are
                  reallocated from the applicable Specified Interest to the
                  Non-Specified Interest or (b) Charged-Off Lease Advances, to
                  the extent that such Charged-Off Lease Advances (i) exceed the
                  portion of the allowance for credit losses related to reserves
                  against such advances not expected to be recovered, as such
                  allowance would appear in the footnotes to the financial
                  statements of the Company and its Restricted Subsidiaries
                  prepared in accordance with GAAP at such time or if
                  specifically identified, elsewhere in such financial
                  statements and (ii) have not already been eliminated in the
                  determination of Leased Vehicles.

                  (h)      The definition of "Lease(s)" in Section 9.1 is hereby
amended and restated in its entirety as follows:

                           LEASE(S) - means the retail agreements for the lease
                  of motor vehicles assigned outright by Dealers to the Company
                  or a Restricted Subsidiary or written by a Dealer in the name
                  of the Company or a Restricted Subsidiary (and funded by the
                  Company or such Restricted Subsidiary) or assigned by Dealers
                  to the Company or a

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                  Restricted Subsidiary, as nominee for the Dealer, for
                  administration, servicing and collection, in each case
                  pursuant to an applicable Dealer Agreement; provided, however,
                  that to the extent the Company or any Restricted Subsidiary
                  transfers or encumbers its interest in any Leases or
                  reallocates such Leases from the Non-Specified Interest to a
                  Specified Interest pursuant to a Permitted Securitization,
                  such Leases shall, from and after the date of such transfer or
                  encumbrance or such reallocation, cease to be considered
                  Leases under this Agreement (reducing the amount of Leased
                  Vehicles by the outstanding amount of Leased Vehicles
                  attributable to such Leases) unless and until such Leases are
                  reassigned to the Company or a Restricted Subsidiary (other
                  than the Titling Subsidiary) or such encumbrances have been
                  discharged or such Leases are reallocated from the applicable
                  Specified Interest to the Non-Specified Interest.

                  (i)      The definition of "Luxembourg Subsidiary" is hereby
added to Section 9.1 to read as follows:

                           LUXEMBOURG SUBSIDIARY - means a wholly-owned direct
                  or indirect Subsidiary organized under the laws of Luxembourg.

                  (j) The definition of "Net Leased Vehicle Dealer Holdbacks" in
Section 9.1 is hereby amended and restated in its entirety as follows:

                           NET LEASED VEHICLE DEALER HOLDBACKS - means, at any
                  time, with respect to Dealer Agreements relating to Leases,
                  amounts due to Dealers at such time from collections of Leased
                  Vehicles by the Company or any Restricted Subsidiary (other
                  than with respect to Leases which have been transferred or
                  encumbered, or reallocated from the Non-Specified Interest to
                  a Specified Interest, pursuant to a Permitted Securitization
                  and (x) have not been reassigned to the Company or a
                  Restricted Subsidiary or the encumbrances on which have not
                  been discharged or (y) have not been reallocated from the
                  applicable Specified Interest to the Non-Specified Interest)
                  pursuant to the applicable Dealer Agreements.

                  (k)      The definition of "Non-Specified Assets" is hereby
added to Section 9.1 to read as follows:

                           NON-SPECIFIED ASSETS - has the meaning ascribed
                  thereto in the Titling Subsidiary Agreements.

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                  (l)      The definition of "Non-Specified Interest" is hereby
added to Section 9.1 to read as follows:

                           NON-SPECIFIED INTEREST - has the meaning ascribed
                  thereto in the Titling Subsidiary Agreements.

                  (m)      The lead-in paragraph and paragraph (b) of the
definition of "Permitted Securitization(s)" are hereby amended and restated in
their entirety as follows:

                           PERMITTED SECURITIZATION(S) - means each transfer or
                  encumbrance (each a "disposition") of specific Advances or
                  Leased Vehicles funded under Back-End Dealer Agreements (and
                  any interest in or lien on the Installment Contracts, Leases,
                  motor vehicles or other rights relating thereto) or of
                  specific Installment Contracts or Leases (and any interest in
                  or lien on motor vehicles or other rights relating thereto)
                  arising under Outright Dealer Agreements and each transfer or
                  encumbrance (also, a "disposition") of a Specified Interest
                  (and the reallocation of Leased Vehicles, Leases and related
                  financial assets from the Non-Specified Interest to such
                  Specified Interest in connection therewith), in each case by
                  the Company or one or more Restricted Subsidiaries to a
                  Special Purpose Subsidiary conducted in accordance with the
                  following requirements:

                                      * * *

                  (b)      (i) The disposition of Advances, Leased Vehicles,
                           Installment Contracts or Leases will not result in
                           the aggregate principal amount of Debt at any time
                           outstanding, and (without duplication) of similar
                           securities at any time issued and outstanding (other
                           than subordinated securities issued to and held by
                           the Company or a Subsidiary), of any Special Purpose
                           Subsidiaries pursuant to Permitted Securitizations
                           exceeding $125,000,000, which amount may be
                           readvanced and reborrowed and (ii) the Company or the
                           Restricted Subsidiary disposing of Advances, Leased
                           Vehicles, Installment Contracts or Leases (directly,
                           or by the transfer or encumbrance or other
                           disposition of a Specified Interest) to a Special
                           Purpose Subsidiary pursuant to such Permitted
                           Securitization shall itself actually receive
                           (substantially contemporaneously with such
                           disposition) cash from each disposition of such
                           financial assets in connection with any such
                           Securitization Transaction in an amount not less than

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                           Seventy-Five Percent (75%) of the sum of (A) the
                           amount of such Advances, (B) the amount of Net
                           Installment Contract Receivables in respect of
                           Installment Contracts arising under Outright Dealer
                           Agreements, and (C) the amount of Leased Vehicles, in
                           each case determined on the date of such
                           Securitization Transaction;

                  (n)      The definition of "Restricted Investment" in Section
9.1 is hereby amended by replacing existing clauses (l) and (m) with the
following:

                           (l)      Intercompany Loans, Advances and Investments
                  by the Company to or in the Titling Subsidiary, each such
                  loan, advance or Investment being (x) allocated to the
                  Non-Specified Interest and made by Company in the ordinary
                  course of conducting its leasing business through the Titling
                  Subsidiary, including without limitation any advances or
                  investments made by the Company (acting as administrative
                  agent under the Titling Subsidiary Agreements) to or in the
                  Titling Subsidiary to reacquire Leases and the related leased
                  vehicles as may be required from time to time under the
                  Titling Subsidiary Agreements but only to the extent such
                  Leases (and leased vehicles) are allocated to the
                  Non-Specified Interest immediately prior to the making of the
                  related loan, advance or investment, or (y) allocated to a
                  Specified Interest and made to reacquire Leases and the
                  related leased vehicles as may be required from time to time
                  under the Titling Subsidiary Agreements but only to the extent
                  such Leases (and leased vehicles) are allocated to the
                  Specified Interest immediately prior to the making of the
                  related loan, advance or investment;

                           (m)      Investments by the Company or any Restricted
                  Subsidiary in the Company, any Restricted Subsidiary or any
                  Special Purpose Subsidiary from and after the effective date
                  of the Fourth Amendment, consisting of (i) dispositions of
                  specific Advances, Leased Vehicles, Installment Contracts
                  (whether assigned outright or related to Advances) or Leases
                  (whether assigned outright or related to Leased Vehicles) made
                  pursuant to a Permitted Securitization and the resultant Debt
                  issued by a Special Purpose Subsidiary to another Subsidiary
                  as part of a Permitted Securitization, in each case to the
                  extent constituting Investments, (ii) advances by the Company,
                  as servicer or administrative agent of the Installment
                  Contracts or Leases covered by a Permitted Securitization or
                  as administrative agent for the Titling Subsidiary under the
                  Titling Subsidiary Agreements, in an aggregate amount not to
                  exceed $1,500,000 outstanding at any time, for the purpose of
                  fulfilling its obligation under applicable

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                  Securitization Documents to (A) advance funds equal to the
                  interest component of obligations issued as part of a
                  Permitted Securitization and payable from collections on such
                  Installment Contracts or Leases, (B) advance funds, upon the
                  expiration or termination of a Lease held by the Titling
                  Subsidiary or a Lease included in a Permitted Securitization,
                  in the amount the Company and its Subsidiaries expect to
                  receive upon the sale or other disposition of the vehicle
                  subject to such Lease or (C) advance funds equal to any
                  portion of the "constant yield payment" (as defined in the
                  Titling Subsidiary Agreements or applicable Securitization
                  Documents) due in any particular period which was not received
                  with respect to a Lease held by the Titling Subsidiary or a
                  securitized Lease (such payments in the case of (A), (B) and
                  (C) of this clause (ii) to be repayable to the Company on a
                  priority basis from such collections, sales or other
                  dispositions), (iii) the repurchase or replacement from and
                  after the date of the effectiveness of the Fourth Amendment of
                  an aggregate amount not to exceed $5,000,000 in Advances,
                  Leased Vehicles, Installment Contracts (whether assigned
                  outright or related to Advances) or Leases (whether assigned
                  outright or related to Leased Vehicles) subsequently
                  determined not to satisfy the eligibility standards contained
                  in the applicable Securitization Documents relating to a
                  Permitted Securitization or otherwise required to be
                  repurchased by the applicable Securitization Documents entered
                  into in compliance with the terms of this Agreement, so long
                  as (x) such replacement is accompanied by the repurchase of or
                  release of encumbrances on such financial assets previously
                  transferred or encumbered pursuant to such securitization and
                  in the amount thereof, (y) any replacement Advances, Leased
                  Vehicles, Installment Contracts (whether assigned outright or
                  related to Advances) or Leases (whether assigned outright or
                  related to Leased Vehicles) are selected by the Company
                  according to the requirements set forth in clause (a) of the
                  definition of Permitted Securitization and (z) such
                  replacements are made at a time when (both before and after
                  giving effect thereto) no Default or Event of Default exists
                  or would exist, (iv) amounts required to fund any Cleanup Call
                  under the terms of such Permitted Securitization, and (v) the
                  disposition of the capital stock of a Special Purpose
                  Subsidiary;

                           (n)      Intercompany Loans, Advances and Investments
                  made pursuant to the UK Restructuring; and

                           (o)      Investments not otherwise included in clause
                  (a) through clause (n) of this definition, provided that the
                  aggregate

                                       13
<PAGE>   14

                  amount of all such Investments does not at any time exceed Two
                  Million Five Hundred Thousand Dollars ($2,500,000).

                  (o)      The definition of "Restricted Subsidiary" in Section
9.1 is hereby amended and restated in its entirety as follows:

                           RESTRICTED SUBSIDIARY -- means any Subsidiary (a) in
                  respect of which the Company owns, directly or indirectly, (i)
                  at least eighty percent (80%) (by number of votes) of each
                  class of such Subsidiary's Voting Stock, or (ii) in the case
                  of CAC Insurance Agency of Ohio, Inc., at least 99% of the
                  shares of capital stock issued and outstanding of all classes
                  in the aggregate, (b) that is organized under the laws of the
                  United States of America or any jurisdiction thereof, the
                  United Kingdom or any jurisdiction thereof (including, without
                  limitation, England, Scotland and Wales), Canada or any
                  jurisdiction thereof, Luxembourg or any jurisdiction thereof
                  or the Republic of Ireland or any jurisdiction thereof, and
                  that conducts all of its business in, and has all of its
                  Property located in, the United States of America, the United
                  Kingdom, Canada, Luxembourg and/or the Republic of Ireland and
                  (c) that is not an Unrestricted Subsidiary. Any Restricted
                  Subsidiary in compliance with the requirements set forth in
                  the first sentence of this definition and designated as a
                  Restricted Subsidiary on the Closing Date shall be deemed to
                  have been a Restricted Subsidiary for all periods prior to the
                  Closing Date. Notwithstanding any provision in Section 6.17 to
                  the contrary, CAC International and CAC UK shall be deemed
                  Restricted Subsidiaries as of October 1, 1995 and CAC of
                  Canada Limited and any Subsidiary formed by the Company to
                  provide property and casualty insurance shall each be deemed a
                  Restricted Subsidiary as of the date of its formation.

                  (p)      The definition of "Scottish Partnership" is hereby
                  added to Section 9.1 to read as follows:

                           SCOTTISH PARTNERSHIP - means a partnership
                  established by the Company under the laws of Scotland pursuant
                  to the UK Restructuring whose partners consist of the Company
                  and a Restricted Subsidiary organized in the United States.

                  (q)      The definition of  "Securitization Property" in
Section 9.1 is hereby amended and restated in its entirety as follows:

                           SECURITIZATION PROPERTY -- means (i) amounts advanced
                  by the Company or a Restricted Subsidiary under a Dealer
                  Agreement  and

                                       14
<PAGE>   15

                  payable from collections, including servicing charges,
                  insurance charges and service policies and all related finance
                  charges, late charges, and all other fees and charges charged
                  to customers and all monies due or to become due, and all
                  monies received, with respect thereto ("Loans"); (ii) all
                  proceeds (including "proceeds" as defined in the Uniform
                  Commercial Code) thereof; (iii) all of the Company's or a
                  Restricted Subsidiary's interest in the Dealer Agreements and
                  Installment Contracts securing payment of Loans, all security
                  interests or liens purporting to secure payment of Loans and
                  all other property obtained upon foreclosure of any security
                  interest securing payment of Loans or any related Installment
                  Contract and all guarantees, insurance (including insurance
                  insuring the priority or perfection of any lien) or other
                  agreements or arrangements of any kind from time to time
                  supporting or securing payment of such Installment Contract
                  whether pursuant to such Installment Contract or otherwise;
                  (iv) all records with respect to Loans, (v) the Company's or a
                  Restricted Subsidiary's right, title and interest in and to
                  business interruption insurance, (vi) all payments received by
                  the Company in respect of Transferred Loans in the form of
                  cash, checks, wire transfers or other form of payment and
                  (vii) a Specified Interest in the Titling Subsidiary.

                  (r)      The definition of  "Securitization Transaction" in
Section 9.1 is hereby amended and restated in its entirety as follows:

                           SECURITIZATION TRANSACTION - means a Transfer of, or
                  grant of a Lien on, Advances, Installment Contracts, Leased
                  Vehicles, Leases, accounts receivable and/or other financial
                  assets by the Company or any Restricted Subsidiary to a
                  Special Purpose Subsidiary or other special purpose or limited
                  purpose entity or the reallocation of Leases and Leased
                  Vehicles (and related financial assets) by the Company or any
                  Restricted Subsidiary from the Non-Specified Interest to a
                  Specified Interest and the transfer of a Specified Interest to
                  a Special Purpose Subsidiary or other special purpose or
                  limited purpose entity and the issuance (whether by such
                  Special Purpose Subsidiary or other special purpose or limited
                  purpose entity or any other Person) of Debt or of any
                  securities secured directly or indirectly by interests in, or
                  of trust certificates, Specified Interests or other securities
                  directly or indirectly evidencing interests in, such Advances,
                  Installment Contracts, Leased Vehicles, Leases, accounts
                  receivable and/or other financial assets.

                                       15
<PAGE>   16

                  (s)      The definition of "Specified Assets" is hereby added
to Section 9.1 to read as follows:

                           SPECIFIED ASSETS - has the meaning ascribed thereto
                  in the Titling Subsidiary Agreements.

                  (t)      The definition of "Specified Interest" is hereby
added to Section 9.1 to read as follows:

                           SPECIFIED INTEREST - has the meaning ascribed thereto
                  in the Titling Subsidiary Agreements.

                  (u)      The definition of "Subsidiary" is hereby amended and
restated in its entirety as follows:

                           SUBSIDIARY - means a corporation, partnership,
                  association, joint stock company, business trust, limited
                  liability company or any other business entity of which the
                  Company owns, directly or indirectly, more than fifty percent
                  (50%) (by number of votes) of each class of the Voting Stock
                  or sufficient equity or voting interests to enable it
                  ordinarily, in the absence of contingencies, to elect a
                  majority of the directors (or Persons performing similar
                  functions) of such entity. Unless otherwise specified to the
                  contrary herein or the context otherwise requires, Subsidiary
                  shall include the Titling Subsidiary.

                  (v)      The definition of "Titling Subsidiary" is hereby
added to Section 9.1 to read as follows:

                           TITLING SUBSIDIARY - means Auto Lease Services LLC, a
                  Delaware limited liability company controlled by the Company
                  and a direct Subsidiary of the Company.

                  (w)      The definition of "Titling Subsidiary Agreements" is
hereby added to Section 9.1 to read as follows:

                           TITLING SUBSIDIARY AGREEMENTS - means that certain
                  Limited Liability Company Agreement of the Titling Subsidiary,
                  dated and effective as of March 1, 2001 (and the related
                  Certificate of Formation, as therein defined), and that
                  certain Administrative Agency Agreement, dated as of March 1,
                  2001, among the Company and the Titling Subsidiary, each as
                  amended (subject to the terms hereof) from time to time.

                                       16
<PAGE>   17

                  (x)      The definition of "UK Restructuring" is hereby added
to Section 9.1 to read as follows:

                           UK RESTRUCTURING - means (i) the creation by the
                  Company of the Scottish Partnership, the Luxembourg Subsidiary
                  and the English Special Purpose Subsidiary, (ii) the
                  capitalization of the Scottish Partnership with CAC UK stock
                  by the Company, (iii) Intercompany Loans from time to time
                  from the Company to the Scottish Partnership in an amount
                  substantially equivalent to the fair market value of assets
                  being transferred to the English Special Purpose Subsidiary at
                  such time by CAC UK, provided that such Intercompany Loans are
                  substantially contemporaneously repaid pursuant to clauses
                  (ix) and (x) of this definition, (iv) the contribution of a
                  nominal amount of capital to the Luxembourg Subsidiary, (v)
                  the contributions to capital from time to time by the Scottish
                  Partnership to the English Special Purpose Subsidiary out of
                  the proceeds of the Company's substantially contemporaneous
                  loan to the Scottish Partnership under clause (iii) of this
                  definition, (vi) Intercompany Loans from time to time by the
                  Scottish Partnership to the Luxembourg Subsidiary out of the
                  proceeds of the Company's substantially contemporaneous loan
                  to the Scottish Partnership under clause (iii) of this
                  definition, (vii) Intercompany Loans from time to time by the
                  Luxembourg Subsidiary to the English Special Purpose
                  Subsidiary substantially equivalent in amount to the
                  substantially contemporaneous loan made to the Luxembourg
                  Subsidiary by the Scottish Partnership, (viii) transfers from
                  time to time of Advances (and its rights in the related
                  Installment Contracts or Leases) by CAC UK to the English
                  Special Purpose Subsidiary for cash consideration in an amount
                  substantially equivalent to the fair market value of the
                  assets being transferred to the English Special Purpose
                  Subsidiary at such time by CAC UK, (ix) dividends from CAC UK
                  to Scottish Partnership in an amount substantially equal to
                  the cash received by CAC UK in exchange for the assets
                  transferred at such time to the English Special Purpose
                  Subsidiary, and (x) repayments from time to time of
                  Intercompany Loans by the Scottish Partnership to the Company.

                  (y)      The definition of "Voting Stock" is hereby added to
Section 9.1 to read as follows:

                           VOTING STOCK - means, with respect to any Person,
                  capital stock (or other equity interests) of any class or
                  classes of a corporation, an association or another business
                  entity the holders of

                                       17
<PAGE>   18

                  which are ordinarily, in the absence of contingencies,
                  entitled to vote in the election of corporate directors (or
                  individuals performing similar functions) of such Person or
                  which permit the holders thereof to control the management of
                  such Person, including general partnership interests in a
                  partnership and membership interests in a limited liability
                  company.

SECTION 3. MISCELLANEOUS

         3.1      COUNTERPARTS. This Sixth Amendment may be executed in any
number of counterparts, each executed counterpart constituting an original, but
all together only one Sixth Amendment.

         3.2      HEADINGS. The headings of the sections of this Sixth Amendment
are for purposes of convenience only and shall not be construed to affect the
meaning or construction of any of the provisions hereof.

         3.3      GOVERNING LAW. This Sixth Amendment shall be governed by and
construed in accordance with the internal laws of the State of New York.

         3.4      EFFECT OF AMENDMENT. Except as expressly provided herein (a)
no other terms and provisions of the Agreement shall be modified or changed by
this Sixth Amendment and (b) the terms and provisions of the Agreement, as
amended by this Sixth Amendment, shall continue in full force and effect. The
Company hereby acknowledges and reaffirms all of its obligations and duties
under the Agreement, as modified by this Sixth Amendment, and the Notes.

         3.5      REFERENCES TO THE AGREEMENT. Any and all notices, requests,
certificates and other instruments executed and delivered concurrently with or
after the execution of the Sixth Amendment may refer to the Agreement without
making specific reference to this Sixth Amendment but nevertheless all such
references shall be deemed to include, to the extent applicable, this Sixth
Amendment unless the context shall otherwise require.

         3.6      COMPLIANCE. The Company certifies that all necessary actions
have been taken by the Company to authorize the execution and delivery of this
Sixth Amendment, and immediately before and after giving effect to this Sixth
Amendment, no Default or Event of Default exists or would exist after giving
effect hereto.

         3.7      EFFECTIVENESS OF AMENDMENTS. The amendments to the Agreement
contemplated by Section 2 hereof shall (in accordance with Section 10.5(a) of
the Agreement) become effective, if at all, at such time as the Company and the
Required Holders of the Notes shall have indicated their written consent to such
amendments by executing and delivering the applicable counterparts of this Sixth
Amendment. It is understood that any holder of Notes may withhold its consent
for any

                                       18
<PAGE>   19

reason, including, without limitation, any failure of the Company to satisfy all
of the following conditions:

                  (a)      This Sixth Amendment shall have been executed and
         delivered by the Company and each of the Required Holders of the Notes.

                  (b)      The execution, delivery and effectiveness of an
         agreement, signed by the Company and the requisite holders of the
         Company's Second Amended and Restated 9.49% Senior Notes due July 1,
         2001 issued under Note Purchase Agreements dated as of August 1, 1996,
         containing an amendment to such Note Purchase Agreements identical in
         substance to the amendment set forth in Section 2 hereof.

                  (c)      The execution, delivery and effectiveness of an
         agreement, signed by the Company and the requisite holders of the
         Company's Second Amended and Restated 10.37% Senior Notes due November
         1, 2001 issued under Note Purchase Agreements dated as of October 1,
         1994, containing an amendment to such Note Purchase Agreements
         identical in substance to the amendment set forth in Section 2 hereof.

                  (d)      The receipt by all holders of Notes of a fee, in
         consideration of the time and expense required to review this
         Amendment, in an amount equal to .04% of the outstanding principal
         amount of the Notes held by such holder as of the date hereof.

                  (e)      The Company shall have paid the statement for
         reasonable fees and disbursements of Bingham Dana LLP, your special
         counsel, presented to the Company on or prior to the effective date of
         this Sixth Amendment.

         3.8      AMENDMENT TO CREDIT AGREEMENT. The Company represents that the
Fifth Amendment to the Credit Agreement, as executed by the "Majority Banks" (as
defined in the Credit Agreement), is in the form attached as Attachment 1 hereto
and in effect on the date of effectiveness of this Sixth Amendment.

         3.9      FULL DISCLOSURE. The Company warrants and represents to you
that, as of the effective date hereof, none of the written statements, documents
or other written materials furnished by, or on behalf of, the Company to you in
connection with the negotiation, execution and delivery of this Sixth Amendment
contain any untrue statement of a material fact or omit a material fact
necessary to make the statements contained therein or herein not misleading in
light of the circumstances in which they were made. There is no fact of which
any of the Company's executive officers has actual knowledge which the Company
has not disclosed to you which materially affects adversely or, so far as the
Company can now reasonably foresee, will materially affect adversely the
business, prospects, profits, Properties or condition (financial or otherwise)
of the Company and the Subsidiaries, taken as a whole, or the ability of the
Company to perform its obligations set forth in the Agreement (after giving
effect to this Sixth Amendment) and the Notes.

                                       19
<PAGE>   20

         3.10     RELEASE OF ENGLISH SHARE CHARGE. The Holders hereby authorize,
pursuant to Section 3(g) of the Intercreditor Agreement, the "Collateral Agent"
under the Intercreditor Agreement to release that certain Deed of Charge dated
as of December 17, 1998 and executed by Company in favor of the Collateral
Agent, provided that, concurrently therewith, the Company shall have granted a
perfected first priority security interest, lien and charge to the "Collateral
Agent" under the Intercreditor Agreement in not less than 65% of the aggregate
partnership interests of the Scottish Partnership as required under Section
6.23(b) of the Agreement, as amended hereby.

      [Remainder of page intentionally blank. Next page is signature page.]

                                       20
<PAGE>   21

         If this Sixth Amendment is satisfactory to you, please sign the form of
acceptance on the enclosed counterpart of this letter and return the same to the
Company, whereupon this Sixth Amendment shall become binding between us in
accordance with its terms.

                                       Very truly yours,

                                       CREDIT ACCEPTANCE CORPORATION

                                       By:/S/ Douglas W. Busk
                                         ---------------------------------
                                                Name: Douglas W. Busk
                                                Title: Chief Financial Officer

   [Signature Page to Sixth Amendment to Note Purchase Agreement in respect of
    9.27% Senior Notes Due October 1, 2001 of Credit Acceptance Corporation]

                                       21
<PAGE>   22

ACCEPTED:
                                     ASSET ALLOCATION & MANAGEMENT
                                     COMPANY AS AGENT FOR AMERICAN
                                     PIONEER LIFE INSURANCE COMPANY
                                     OF NEW YORK

                                     By/S/ Kathy Lange
                                       ---------------------------------
                                              Name: Kathy Lange
                                              Title:

                                     ASSET ALLOCATION & MANAGEMENT
                                     COMPANY AS AGENT FOR AMERICAN
                                     PROGRESSIVE LIFE AND HEALTH
                                     INSURANCE COMPANY OF NEW YORK

                                     By/S/ Kathy Lange
                                       ---------------------------------
                                              Name: Kathy Lange
                                              Title:

                                     ASSET ALLOCATION & MANAGEMENT
                                     COMPANY AS AGENT FOR FEDERATED
                                     RURAL ELECTRIC INSURANCE CORP.

                                     By/S/ Kathy Lange
                                       ---------------------------------
                                              Name: Kathy Lange
                                              Title:

                                     ASSET ALLOCATION & MANAGEMENT
                                     COMPANY AS AGENT FOR TOWER
                                     LIFE INSURANCE COMPANY

                                     By/S/ Kathy Lange
                                       ---------------------------------
                                              Name: Kathy Lange
                                              Title:

                                     ASSET ALLOCATION & MANAGEMENT
                                     COMPANY AS AGENT FOR MUTUAL
                                     PROTECTIVE INSURANCE COMPANY

                                     By/S/ Kathy Lange
                                       ---------------------------------
                                              Name: Kathy Lange
                                              Title:

   [Signature Page to Sixth Amendment to Note Purchase Agreement in respect of

<PAGE>   23

    9.27% Senior Notes Due October 1, 2001 of Credit Acceptance Corporation]

<PAGE>   24

                                     ASSET ALLOCATION & MANAGEMENT
                                     COMPANY AS AGENT FOR
                                     PHYSICIANS LIFE INSURANCE COMPANY VISTA 500

                                     By/S/ Peter Maurogenes
                                       ---------------------------------
                                              Name: Peter Maurogenes
                                              Title: Partner

                                     ASSET ALLOCATION & MANAGEMENT
                                     COMPANY AS AGENT FOR WORLD
                                     INSURANCE COMPANY

                                     By/S/ Peter Maurogenes
                                       ---------------------------------
                                              Name: Peter Maurogenes
                                              Title: Partner

                                     ASSET ALLOCATION & MANAGEMENT
                                     COMPANY AS AGENT FOR VESTA
                                     FIRE INSURANCE CORPORATION

                                     By/S/ Peter Maurogenes
                                       ---------------------------------
                                              Name: Peter Maurogenes
                                              Title: Partner

                                     ASSET ALLOCATION & MANAGEMENT
                                     COMPANY AS AGENT FOR MEDICO
                                     LIFE INSURANCE COMPANY

                                     By/S/ Peter Maurogenes
                                       ---------------------------------
                                              Name: Peter Maurogenes
                                              Title: Partner

   [Signature Page to Sixth Amendment to Note Purchase Agreement in respect of
    9.27% Senior Notes Due October 1, 2001 of Credit Acceptance Corporation]

<PAGE>   25

                                     ANNEX I
                 SECOND AMENDED AND RESTATED 9.27% SENIOR NOTES
                               DUE OCTOBER 1, 2001

American Pioneer Life Insurance Company of New York American Progressive Life
and Health Insurance Company of New York
Federated Rural Electric Insurance Corp.
Tower Life Insurance Company
Physicians Life Insurance Company Vista 500
World Insurance Company
Vesta Fire Insurance Corporation
Mutual Protective Insurance Company
Medico Life Insurance Company<PAGE>   1
                                                                EXHIBIT 4(f)(13)

                               AMENDMENT NO. 4 TO
                               SECURITY AGREEMENT

                  AMENDMENT NO. 4 TO SECURITY AGREEMENT (this "Amendment"),
dated as of March 12, 2001, among KITTY HAWK FUNDING CORPORATION, a Delaware
corporation, as a secured party (together with its successors and assigns, the
"Company"), CAC FUNDING CORP., a Nevada corporation, as debtor (together with
its successors and assigns, the "Debtor"), CREDIT ACCEPTANCE CORPORATION, a
Michigan corporation, individually and as servicer (together with its successors
and assigns, the "Servicer"), and BANK OF AMERICA, N.A., a national banking
association ("Bank of America"), individually and as collateral agent (together
with its successors and assigns in such capacity, the "Collateral Agent"),
amending that certain Security Agreement (as amended to the date hereof, the
"Security Agreement"), dated as of July 7, 1998, between the Company, the
Debtor, the Servicer and Bank of America (known under the Security Agreement as
"NationsBank, N.A."), individually and as Collateral Agent.

                  WHEREAS, on the terms and conditions set forth herein, the
parties to the Security Agreement wish to amend the Security Agreement as
provided herein.

                  NOW, THEREFORE, the parties hEREBY AGREE AS FOLLOWS:

                  SECTION 1.  DEFINED TERMS.  AS USED IN THIS AMENDMENT
CAPITALIZED TERMS HAVE THE SAME MEANINGS ASSIGNED THERETO IN THE SECURITY
AGREEMENT.

                  SECTION 2.  AMENDMENTS.

         (1)      SECTION 1.1 OF THE SECURITY AGREEMENT IS HEREBY AMENDED BY
DELETING THE DEFINITION OF "INSURANCE POLICY".

         (2)      SECTION 3.4 OF THE SECURITY AGREEMENT IS HEREBY AMENDED BY
DELETING ALL OF THE LANGUAGE IN SUCH SECTION AND REPLACING IT WITH "RESERVED".

         (3)      SECTION 3.5 OF THE SECURITY AGREEMENT IS HEREBY AMENDED BY
DELETING ALL OF THE LANGUAGE IN SUCH SECTION AND REPLACING IT WITH "RESERVED".

                                       1
<PAGE>   2

                  SECTION 3.  REPRESENTATIONS AND WARRANTIES.

         (a)      THE DEBTOR HEREBY MAKES TO THE COLLATERAL AGENT, THE COMPANY
AND THE BANK INVESTORS, ON AND AS OF THE DATE HEREOF, ALL OF THE REPRESENTATIONS
AND WARRANTIES SET FORTH IN SECTIONS 3.1 AND 3.2 OF THE SECURITY AGREEMENT,
EXCEPT THAT TO THE EXTENT THAT ANY OF SUCH REPRESENTATIONS AND WARRANTIES
EXPRESSLY RELATE TO AN EARLIER DATE, SUCH REPRESENTATIONS AND WARRANTIES SHALL
BE TRUE AND CORRECT AS OF SUCH EARLIER DATE.

                  SECTION 4. EFFECTIVENESS. THIS AMENDMENT SHALL BECOME
EFFECTIVE ON THE DATE HEREOF.

                  SECTION 5. COSTS AND EXPENSES. THE DEBTOR SHALL PAY ALL OF THE
COMPANY'S, THE BANK INVESTORS' AND THE COLLATERAL AGENT'S COST AND EXPENSES
(INCLUDING OUT OF POCKET EXPENSES AND REASONABLE ATTORNEYS FEES AND
DISBURSEMENTS) INCURRED BY THEM IN CONNECTION WITH THE PREPARATION, EXECUTION
AND DELIVERY OF THIS AMENDMENT.

                  SECTION 6. GOVERNING LAW. THIS AMENDMENT SHALL BE GOVERNED BY
AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

                  SECTION 7. SEVERABILITY; COUNTERPARTS. THIS AMENDMENT MAY BE
EXECUTED IN ANY NUMBER OF COUNTERPARTS AND BY DIFFERENT PARTIES HERETO IN
SEPARATE COUNTERPARTS, EACH OF WHICH WHEN SO EXECUTED SHALL BE DEEMED TO BE AN
ORIGINAL AND ALL OF WHICH WHEN TAKEN TOGETHER SHALL CONSTITUTE ONE AND THE SAME
INSTRUMENT. ANY PROVISIONS OF THIS AMENDMENT WHICH ARE PROHIBITED OR
UNENFORCEABLE IN ANY JURISDICTION SHALL, AS TO SUCH JURISDICTION, BE INEFFECTIVE
TO THE EXTENT OF SUCH PROHIBITION OR UNENFORCEABILITY WITHOUT INVALIDATING THE
REMAINING PROVISIONS HEREOF, AND ANY SUCH PROHIBITION OR UNENFORCEABILITY IN ANY
JURISDICTION SHALL NOT INVALIDATE OR RENDER UNENFORCEABLE SUCH PROVISION IN ANY
OTHER JURISDICTION.

                  SECTION 8. CAPTIONS. THE CAPTIONS IN THIS AMENDMENT ARE FOR
CONVENIENCE OF REFERENCE ONLY AND SHALL NOT DEFINE OR LIMIT ANY OF THE TERMS OR
PROVISIONS HEREOF.

                  SECTION 9. RATIFICATION. EXCEPT AS EXPRESSLY AFFECTED BY THE

                                       2
<PAGE>   3

PROVISIONS HEREOF, THE SECURITY AGREEMENT AS AMENDED SHALL REMAIN IN FULL FORCE
AND EFFECT IN ACCORDANCE WITH ITS TERMS AND RATIFIED AND CONFIRMED BY THE
PARTIES HERETO. ON AND AFTER THE DATE HEREOF, EACH REFERENCE IN THE SECURITY
AGREEMENT TO "THIS AGREEMENT", "HEREUNDER", "HEREIN" OR WORDS OF LIKE IMPORT
SHALL MEAN AND BE A REFERENCE TO THE SECURITY AGREEMENT AS AMENDED BY THIS
AMENDMENT.

                                       3
<PAGE>   4

                  IN WITNESS WHEREOF, THE PARTIES HERETO HAVE EXECUTED AND
DELIVERED THIS AMENDMENT NO. 4 TO THE SECURITY AGREEMENT AS OF THE DATE FIRST
WRITTEN ABOVE.

                            CAC FUNDING CORP., AS DEBTOR

                            BY: /S/ DOUGLAS W. BUSK
                                NAME: DOUGLAS W. BUSK
                                TITLE: CHIEF FINANCIAL OFFICER

                            CREDIT ACCEPTANCE CORPORATION,
                            INDIVIDUALLY AND AS SERVICER

                            BY: /S/ DOUGLAS W. BUSK
                                -------------------------------------------
                                NAME: DOUGLAS W. BUSK
                                TITLE: CHIEF FINANCIAL OFFICER

                            KITTY HAWK FUNDING CORPORATION,
                             AS COMPANY

                            BY: /S/ ANDY YAN
                                -------------------------------------------
                                NAME:
                                TITLE:

                            BANK OF AMERICA, N.A., INDIVIDUALLY
                            AND AS COLLATERAL AGENT

                            BY: /S/ MICHELLE M. HEATH
                                ------------------------------------------
                                NAME: MICHELLE HEATH
                                TITLE: MANAGING DIRECTOR

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