<PAGE>
 
             FOURTH AMENDMENT TO LOAN AGREEMENT DATED JUNE 28, 1994
             ------------------------------------------------------


          This Fourth Amendment to Loan Agreement is hereby made and entered
into on this 29th day of February, 1996, by and between NationsBank of
Tennessee, N.A. (hereinafter referred to as "Lender") and Miller Industries,
Inc. (hereinafter referred to as "Borrower") and Century Holdings, Inc.,
Champion Carrier Corporation, Miller Industries Towing Equipment, Inc. f/k/a
Century Wrecker Corporation and Century Finance Group, Inc. (hereinafter
collectively referred to as "Guarantor") and Miller Industries International,
Inc. (hereinafter referred to as "New Guarantor");

                              W I T N E S S E T H
                              - - - - - - - - - -

          WHEREAS, Lender, Century Wrecker Corporation, Century Holdings, Inc.
and Champion Carrier Corporation, as Guarantors, and Miller Industries, Inc., as
Borrower, entered into a Loan Agreement dated June 28, 1994 (hereinafter
referred to as the "Loan Agreement") whereby Lender agreed to loan to Borrower
up to Fifteen Million Dollars ($15,000,000) (hereinafter referred to as the
"Loan"), and whereby Century Holdings, Inc., Champion Carrier Corporation and
Century Wrecker Corporation agreed to guarantee all of the Obligations (as that
term is defined in the Loan Agreement) of the Borrower to Lender by each
separately executing Guaranty Agreements (hereinafter referred to as the
"Guaranty Agreements"); and

          WHEREAS, pursuant to an Amendment to Certain Loan Documents dated
December 30, 1994, by and between Lender and Miller Industries Towing Equipment,
Inc. f/k/a Century Wrecker Corporation and Century Finance Group, Inc., the Loan
Agreement was amended to reflect the merger of Century Wrecker Corporation and
Century Finance Group, Inc. and the name change of the merged entities to Miller
Industries Towing Equipment, Inc., to recognize the liability and obligation of
Miller Industries Towing Equipment, Inc., as a Guarantor under the Loan
Agreement and Loan Documents in the place of Century Wrecker Corporation and to
amend Section 7.6 of the Loan Agreement to allow the merger and name change; and
      -----------                                                               

          WHEREAS, on or about March 30, 1995, the Lender, Borrower and
Guarantors entered into a Second Amended Loan Agreement whereby the interest
rate payable by Borrower to Lender on the Revolving Line of Credit was amended;
and

          WHEREAS, on or about December 29, 1995, Lender, Borrower, Guarantors
and New Guarantor entered into a Third Amended Loan Agreement and Amendment to
Guaranty Agreements whereby the amount of indebtedness under the Loan was
increased from $15,000,000 to an amount up to $25,000,000, the interest rate was
amended, the financial covenants were revised, the Guarantors affirmed and
confirmed their guaranty of the Obligations of Borrower to Lender including the
increase in the indebtedness to an amount up to $25,000,000 and New Guarantor
agreed to guarantee all of the Obligations of
<PAGE>
 
Borrower to Lender and to be bound by the terms of the Loan Agreement and all
amendments thereto; and

          WHEREAS, Lender has agreed to loan to Guarantor Champion Carrier
Corporation the principal sum of Seven Hundred Thousand Dollars ($700,000) for
the purchase of an existing facility which is located in Hermitage, Pennsylvania
plus five acres in addition to completing a 22,500 square foot expansion of the
existing facility and such loan is contemplated in the Loan Agreement as a
permitted lien (hereinafter the "$700,000 Loan"); and

          WHEREAS, New Guarantor, Guarantors, Lenders and Borrower desire that
an event of default under the $700,000 Loan from Lender to Guarantor Champion
Carrier Corporation and the loan documents executed pursuant thereto
(hereinafter the "$700,000 Loan Documents") constitute an event of default under
this Loan Agreement.

          NOW, THEREFORE, in consideration of the premises and for other good
and valuable consideration, the receipt and adequacy of which is hereby
acknowledged, the parties do hereby agree as follows:

1.   The Loan Agreement is hereby amended to add an event of default as follows:

     (a)  Section 9.1 of the Loan Agreement is amended to add Section 9.1(p)
          -----------                                         --------------
     which states as follows:

          Section 9.1(p).  There occurs an event of default under the terms and
          --------------                                                       
          conditions of the Loan Agreement executed by and between Lender and
          Guarantor Champion Carrier Corporation dated _____________________,
          1996, or under the terms and conditions of any of the Loan Documents
          (as such term is defined in the Loan Agreement dated ______________,
          1996) executed pursuant to such Loan Agreement.

2.   All of the terms and conditions of the Loan Agreement and Amendment to
     Certain Loan Documents not specifically amended herein, are hereby
     incorporated by reference and are confirmed by the Borrower, Miller
     Industries Towing Equipment, Inc., Champion Carrier Corporation, Century
     Holdings, Inc. and Miller Industries International, Inc. to remain in full
     force and effect.

          IN WITNESS WHEREOF, the parties hereby have executed this Agreement on
the date first above written.


                                       2
<PAGE>
 
                              NATIONSBANK OF TENNESSEE, N.A.


                              By:  /s/ 
                                 -------------------------------
                              Title:  Senior Vice President
                                    ----------------------------
                                                        LENDER



                              CENTURY HOLDINGS, INC.


                              By:  /s/
                                 -------------------------------
                              Title:
                                    ----------------------------
                                                       GUARANTOR



                              CHAMPION CARRIER CORPORATION


                              By:  /s/
                                 -------------------------------
                              Title:
                                    ----------------------------  
                                                       GUARANTOR



                              MILLER INDUSTRIES INTERNATIONAL, INC.


                              By:  /s/
                                 -------------------------------
                              Title:
                                    ----------------------------


                                       3
<PAGE>
 
                              MILLER INDUSTRIES TOWING EQUIPMENT, INC. f/k/a
                              Century Wrecker Corporation and Century Finance
                              Group, Inc.


                              By:  /s/
                                 -------------------------------
                              Title:
                                    ----------------------------
                                                       GUARANTOR



                              MILLER INDUSTRIES, INC.


                              By:  /s/
                                 -------------------------------
                              Title:
                                    ----------------------------
                                                        BORROWER

                                       4