<PAGE>   1

                                                                  EXHIBIT 10.45

                               AMENDMENT NO. 4 TO
                          LOAN AND SECURITY AGREEMENT
                          ---------------------------

                  AMENDMENT NO. 4, dated as of November 22, 1997, to the LOAN
AND SECURITY AGREEMENT, dated as of March 28, 1997, as amended by the FIRST
AMENDMENT dated as of April 10, 1997, the SECOND AMENDMENT dated as of July 1,
1997, and the THIRD AMENDMENT dated as of August 1, 1997 (as so amended, the
"Loan and Security Agreement"), between FOOTHILL CAPITAL CORPORATION, a
California corporation, with a place of business located at 11111 Santa Monica
Boulevard, Suite 1500, Los Angeles, California 90025-3333, and DORSEY TRAILERS,
INC., a Delaware corporation, with its chief executive offices located at 2727
Paces Ferry Road, One Paces Ferry West, Suite 1700, Atlanta, Georgia 30339.

                                    Preamble
                                  
                  The Borrower has requested Foothill to amend the Loan and
Security Agreement to (i) increase the concentration limit on Eligible Accounts
with respect to which Southeast Freight Lines, STI Credit Corporation,
Professional Transportation Group, Roadway Package System and Ryder System Inc.
are Account Debtors, (ii) amend the amortization schedule of the term loan,
(iii) increase the interest rate on the term loan from 2.0 percentage points
above the Reference Rate to 3.0 percentage points above the Reference Rate
commencing on May 1, 1998, and (iv) provide for a $500,000 overadvance through
December 15, 1997 which overadvance may be increased up to $1,000,000 from
December 1, 1997 through December 5, 1997. Accordingly, the Borrower and
Foothill hereby agree as follows:

                  1. Definitions. All terms used herein which are defined in
the Loan and Security Agreement and not otherwise defined herein are used
herein as defined therein.

                  2. Section 1.1 of the Loan and Security Agreement. Section
1.1 of the Loan and Security Agreement is hereby amended as follows:

                  (a) Eligible Accounts. Paragraph (h) of the definition of the
term "Eligible Accounts" is hereby amended in its entirety to read as follows:

                           "(h) Accounts with respect to an Account Debtor,
                  whose total obligations owing to Borrower exceed 20% of all
                  Eligible Accounts (other than (i) from August 1, 1997 through
                  June 30, 1998, Accounts with respect to which the Account
                  Debtor is Ryder System Inc. where the total obligations owing
                  by Ryder System Inc. to Borrower do not exceed 40% of all
                  Eligible Accounts, (ii) from November 22, 1997 through
                  January 31, 1998, Accounts with respect to which the





                          
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                  Account Debtor is Southeast Freight Lines where the total
                  obligations owing by Southeast Freight Lines to Borrower do
                  not exceed 40% of all Eligible Accounts, (iii) from November
                  22, 1997 through January 31, 1998, Accounts with respect to
                  which the Account Debtor is STI Credit Corporation where the
                  total obligations owing by STI Credit Corporation to Borrower
                  do not exceed 40% of all Eligible Accounts, (iv) from
                  November 22, 1997 through January 31, 1998, Accounts with
                  respect to which the Account Debtor is Professional
                  Transportation Group where the total obligations owing by
                  Professional Transportation Group to Borrower do not exceed
                  40% of all Eligible Accounts, and (v) from November 22, 1997
                  through June 30, 1998, Accounts with respect to which the
                  Account Debtor is Roadway Package System where the total
                  obligations owing by Roadway Package System to Borrower do
                  not exceed 40% of all Eligible Accounts), to the extent of
                  the obligations owing by such Account Debtor in excess of
                  such percentages, provided that, upon the request of
                  Borrower, Foothill may waive or increase the limitation if in
                  its reasonable credit judgment, the Account Debtor is
                  considered credit worthy, such waiver and/or increase by
                  Foothill not to be unreasonably withheld or delayed;"

                  (b) Overadvance Amount. The definition of the term
"Overadvance Amount" is hereby added to read as follows:

                           ""Overadvance Amount." means (i) $500,000, from
                  November 26, 1997 through and including December 15, 1997,
                  and (ii) $0.00, after December 15, 1997, provided, however,
                  Foothill may in its sole discretion increase the Overadvance
                  Amount to $1,000,000 from December 1, 1997 through and
                  including December 5, 1997."

                  3. Borrowing Base. (a) Clause (x) of Section 2.1(a) of the
Loan and Security Agreement is hereby amended in its entirety to read as
follows:

                           "(x) the sum of (I) the lesser of (i) (A) 80% of
                  Eligible Accounts other than that portion of any Eligible
                  Accounts that (1) is or will be satisfied by the transfer to
                  the Borrower of Used Trailer Inventory or (2) is subject to a
                  Contra Obligation, less (B) the amount, if any, of the
                  Dilution Reserve, and (ii) on and after June 1, 1997, an
                  amount equal to Borrower's Collections with respect to
                  Accounts for the immediately preceding 30 day period, and
                  (II) the Overadvance Amount, plus"


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<PAGE>   3

                  4. Term Loan. Section 2.3 of the Loan and Security Agreement
is hereby amended by deleting the following:

                           "The Term Loan shall be repaid in eight (8)
                  installments of principal in the following amounts:

<TABLE>
<CAPTION>
=================================================================
           DATE                             INSTALLMENT AMOUNT
=================================================================
<S>                                         <C>
      October 1, 1997                            $250,000
-----------------------------------------------------------------
     November 1, 1997                            $250,000
-----------------------------------------------------------------
     December 1, 1997                            $250,000
-----------------------------------------------------------------
      January 1, 1998                            $250,000
-----------------------------------------------------------------
     February 1, 1998                            $250,000
-----------------------------------------------------------------
      March, 1, 1998                             $250,000
-----------------------------------------------------------------
       April 1, 1998                             $250,000
-----------------------------------------------------------------
        May 1, 1998                              $250,000         ;"
=================================================================
</TABLE>

and substituting in lieu thereof:

                           "The Term Loan shall be repaid in eight (8)
                  installments of payment in the following amounts:


<TABLE>
<CAPTION>
=================================================================
            DATE                         INSTALLMENT AMOUNT
=================================================================
<S>                                      <C>     
       October 1, 1997                        $250,000
-----------------------------------------------------------------
      November 1, 1997                        $250,000
-----------------------------------------------------------------
      December 1, 1997                        $      0
-----------------------------------------------------------------
       January 1, 1998                        $      0
-----------------------------------------------------------------
      February 1, 1998                        $250,000
-----------------------------------------------------------------
       March, 1, 1998                         $250,000
-----------------------------------------------------------------
        April 1, 1998                         $250,000
-----------------------------------------------------------------
         May 1, 1998                          $250,000
-----------------------------------------------------------------
        June 1, 1998                          $250,000
-----------------------------------------------------------------
        July 1, 1998                          $250,000            ."
=================================================================
</TABLE>

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                  5. Interest Rate. Section 2.5(a) of the Loan and Security
Agreement is hereby amended in its entirety to read as follows:

                           "(a) Interest Rate. Except as provided in clause (b)
                  below, all obligations (except for undrawn Letters of
                  Credit), shall bear interest at a per annum rate of 2.0
                  percentage points above the Reference Rate, provided that
                  from and after May 1, 1998, the outstanding payment amount of
                  the Term Loan shall bear interest at a rate per annum of 3.0
                  percentage points above the Reference Rate."

                  6. Section 2.10 of the Loan and Security Agreement. Section
2.10 of the Loan and Security Agreement is hereby amended by adding at the end
thereof a new section 2.10(g) as follows:

                           "(g) Overadvance Fee. If, on any day after December
                  15, 1997, an Overadvance exists, at the election of Foothill,
                  the Borrower will pay Foothill a fee equal $1,000 per day for
                  each day that an Overadvance exists."

                  7. Conditions. This Amendment shall become effective only
upon satisfaction in full of the following conditions precedent (the first date
upon which all such conditions have been satisfied being herein called the
"Effective Date"):

                  (a) The representations and warranties contained in this
Amendment and in Section 5 of the Loan and Security Agreement and each other
Loan Document shall be correct on and as of the Effective Date as though made
on and as of such date (except where such representations and warranties relate
to an earlier date in which case such representations and warranties shall be
true and correct as of such earlier date); no Default or Event of Default shall
have occurred and be continuing on the Effective Date or result from this
Amendment becoming effective in accordance with its terms.

                  (b) Foothill shall have received a counterpart of this
Amendment, duly executed by the Borrower.

                  (c) The Borrower shall pay to Foothill a non-refundable
amendment fee of $20,000, which fee is earned in full on the date hereof.

                  (d) All legal matters incident to this Amendment shall be
satisfactory to Foothill and its counsel.

                  8. Representations and Warranties. The Borrower hereby
represents and warrants to Foothill as follows:

                  (a) The Borrower (i) is a corporation duly organized, validly
existing and in good standing under the laws of the State of Delaware and (ii)
has all requisite corporate power, authority and legal right to execute,
deliver and perform this Amendment, and to perform the Loan and Security
Agreement, as amended hereby.





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                  (b) The execution, delivery and performance of this Amendment
by the Borrower, and the performance by the Borrower of the Loan and Security
Agreement, as amended hereby (i) have been duly authorized by all necessary
corporate action, (ii) do not and will not contravene its charter or by-laws or
any applicable law, and (iii) except as provided in the Loan Documents, do not
and will not result in the creation of any Lien upon or with respect to any of
its respective properties.

                  (c) This Amendment and the Loan and Security Agreement, as
amended hereby, constitute the legal, valid and binding obligations of the
Borrower, enforceable against the Borrower in accordance with its terms.

                  (d) No authorization or approval or other action by, and no
notice to or filing with, any Governmental Authority is required in connection
with the due execution, delivery and performance by the Borrower of this
Amendment and the performance by the Borrower of the Loan and Security
Agreement as amended hereby.

                  (e) The representations and warranties contained in Section 7
of the Loan and Security Agreement and each other Loan Document are correct on
and as of the Effective Date as though made on and as of the Effective Date
(except to the extent such representations and warranties expressly relate to
an earlier date in which case such representations and warranties shall be true
and correct as of such earlier date), and no Default or Event of Default has
occurred and is continuing on and as of the Effective Date or will result from
this Amendment becoming effective in accordance with its terms.

                  9.  Continued Effectiveness of the Loan and Security Agreement
and Loan Documents. The Borrower hereby (i) confirms and agrees that each Loan
Document to which it is a party is, and shall continue to be, in full force and
effect and is hereby ratified and confirmed in all respects except that on and
after the Effective Date of this Amendment all references in any such Loan
Document to "the Loan and Security Agreement", the "Agreement", "thereto",
"thereof", "thereunder" or words of like import referring to the Loan and
Security Agreement shall mean the Loan and Security Agreement as amended by
this Amendment; and (ii) confirms and agrees that to the extent that any such
Loan Document purports to assign or pledge to Foothill, or to grant a security
interest in or Lien on, any collateral as security for the obligations of the
Borrower from time to time existing in respect of the Loan and Security
Agreement and the Loan Documents, such pledge, assignment and/or grant of the
security interest or Lien is hereby ratified and confirmed in all respects.

                  10. Miscellaneous.

                  (a) This Amendment may be executed in any number of
counterparts and by different parties hereto in separate counterparts, each of
which shall be deemed to be an original but all of which taken together shall
constitute one and the same agreement.

                  (b) Section and paragraph headings herein are included for
convenience of reference only and shall not constitute a part of this Amendment
for any other purpose.




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<PAGE>   6

                  (c) This Amendment shall be governed by, and construed in
accordance with, the laws of the State of California.

                  (d) The Borrower will pay on demand all reasonable fees,
costs and expenses of Foothill in connection with the preparation, execution
and delivery of this Amendment including, without limitation, reasonable fees
disbursements and other charges of Schulte Roth & Zabel LLP, counsel to
Foothill.


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<PAGE>   7



                  IN WITNESS WHEREOF, the parties hereto have caused this
Amendment to be executed and delivered.

                                       DORSEY TRAILERS, INC.,
                                       a Delaware corporation


                                       By: /s/ James E. Clements
                                          -------------------------------------
                                          Name: James E. Clements
                                          Title: Vice President Finance

                                       FOOTHILL CAPITAL CORPORATION,
                                       a California corporation

                                       By:  /s/ Anthony Aloi
                                          -------------------------------------
                                          Name: Anthony Aloi
                                          Title: Assistant Vice President





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