<PAGE>

                                                                    EXHIBIT 4.52

                                                                  EXECUTION COPY

                                FOURTH AMENDMENT

                  FOURTH AMENDMENT, dated as of September 28, 2001 (this
"Amendment"), to the Amended and Restated Credit Agreement, dated as of June 30,
2000 (such Credit Agreement, as heretofore amended, supplemented or otherwise
modified, the "Credit Agreement"), among ANC RENTAL CORPORATION, a Delaware
corporation (the "Borrower"), the several Lenders from time to time parties
thereto, LEHMAN BROTHERS INC., as advisor, lead arranger and book manager, and
LEHMAN COMMERCIAL PAPER INC., as syndication agent and as administrative agent
(in such capacity, the "Administrative Agent").

                              W I T N E S S E T H:

                  WHEREAS, the Borrower has requested that the Lenders amend
certain provisions of the Credit Agreement; and

                  WHEREAS, the Lenders have agreed to amend the Credit
Agreement, but only upon the terms and subject to the conditions set forth
below;

                  NOW, THEREFORE, in consideration of the premises and mutual
agreements contained herein, and for other valuable consideration, the receipt
of which is hereby acknowledged, the Borrower, the Lenders and the Agents hereby
agree as follows:

                  1.       Definitions. All terms defined in the Credit
Agreement shall have such defined meanings when used herein unless otherwise
defined herein.

                  2.       Amendment to Section 1.1 (Defined Terms). Section 1.1
of the Credit Agreement is hereby amended by inserting the following defined
terms in their appropriate alphabetical order:

                           "Fourth Amendment": the Fourth Amendment, dated as
         of September 28, 2001, to this Agreement.

                           "Fourth Amendment Effective Date": the effective date
         of the Fourth Amendment.

                           "Interim Loan Facility Extension": the Sixteenth
         Amendment to the Interim Loan Agreement, in the form attached hereto as
         Exhibit A, which shall include an extension until November 30, 2001 of
         the mandatory prepayment due September 30, 2001.

                  3.       Amendment of Section 5.2 (Certificates; Other
Information). Section 5.2 of the Credit Agreement is hereby amended by (a)
deleting the reference in the introductory clause thereof to "clause (f)" and
substituting in lieu thereof "clause (g)", (b) deleting "and" at the end of
clause (e) thereof, (c) relettering clause (f) thereof as clause (g) and (d)
adding a new clause (f) immediately after clause (e) thereof as follows:
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                                                                               2


                  "(f) copies of all information and reports delivered to the
         lenders or the administrative agent under the Interim Loan Facility
         concurrently with the delivery of such information and reports to such
         lenders or administrative agent; and".

                  4.       Amendment of Section 5 (Affirmative Covenants).
Section 5 of the Credit Agreement is hereby amended by adding at the end thereof
new Sections 5.13, 5.14 and 5.15 as follows:

                  "5.13 Pursuit of Transactions. Continue to pursue strategic
         alternatives for the Borrower and its Subsidiaries as described in the
         Borrower's Form 8-K report dated August 2, 2001, including, without
         limitation, transactions proposed or under discussion prior to
         September 19, 2001, and transactions that may be proposed after
         September 19, 2001, in each case providing for the sale, upon
         commercially reasonable terms, of all of, or discrete portions of, the
         business of the Borrower and its Subsidiaries or for the investment in
         the Borrower of additional equity.

                  5.14 Crisis Manager. Continue to retain William N. Plamondon
         as a crisis manager (or his successor or his replacement crisis manager
         reasonably satisfactory to the Administrative Agent) which crisis
         manager shall be permitted to communicate directly with the
         Administrative Agent and the Borrower's board of directors to, among
         other things, (a) assist the Borrower and its Subsidiaries with (i) the
         strategic and operational decisions of the Borrower and its
         Subsidiaries as requested by the board of directors of the Borrower,
         (ii) the modification and enhancement of the management information
         systems and reporting systems of the Borrower and its Subsidiaries and
         (iii) the management of and communications with its creditors and other
         parties, (b) supplement the treasury and finance staff of the Borrower
         and its Subsidiaries as needed and (c) make recommendations to conserve
         and generate cash and liquidity for the Borrower and its Subsidiaries.

                  5.15. Sales of Property. Continue to pursue the sale on
         commercially reasonable terms of property owned by the Borrower or any
         Subsidiary thereof which is neither material nor necessary to the
         operations of the business of the Borrower and its Subsidiaries.".

                  5.       Section 6.15 (Limitation on Lines of Business).
Section 6.15 of the Credit Agreement is hereby amended by adding at the end
thereof immediately before the period the following: "provided, however, the
Borrower will not, and the Borrower will not permit any of its Subsidiaries to,
directly or indirectly, extend or expand the business conducted by the Alamo
Local Market Division of the Borrower".

                  6.       Amendment of Section 6.1 (Financial Condition
Covenants). Sections 6.1(a), (b) and (c) of the Credit Agreement are hereby
amended by adding at the end of each such Section immediately after the table
contained therein the following: "; provided that until November 15, 2001, the
Borrower shall not be required to comply with the foregoing covenant (which
covenant shall be suspended until such date) for the period of four consecutive
fiscal quarters of the Borrower ending with FQ3 2001.".
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                                                                               3


                  7.       Amendment of Section 6.7 (Limitation on Capital
Expenditures). Section 6.7 of the Credit Agreement is hereby amended by adding
at the end thereof immediately before the period the following: "provided,
further, that for the months of October, 2001 and November, 2001, any such
Capital Expenditures shall not exceed $2,500,000 for each such month".

                  8.       Amendment of Section 6.9 (Limitation on Optional
Payments and Modifications of Debt Instruments, etc.). Section 6.9 of the Credit
Agreement is hereby amended by:

                  (a) deleting clause (iii) in paragraph (a) thereof and
relettering clause (iv) thereof as clause (iii); and

                  (b) adding immediately after "contemplated by the Interim Loan
Facility Amendment" at the end of clause (ii) in paragraph (b) thereof "and by
the Interim Loan Facility Extension".

                  9.       Representations; No Default. On and as of the date
hereof, and after giving effect to this Amendment, (a) the Borrower certifies
that no Default or Event of Default has occurred or is continuing, and (b) the
Borrower confirms, reaffirms and restates that the representations and
warranties set forth in Section 3 of the Credit Agreement and in the other Loan
Documents are true and correct in all material respects, provided that (i) the
references to the Credit Agreement therein shall be deemed to be references to
this Amendment and to the Credit Agreement as amended by this Amendment and (ii)
for purposes of this Section 9 the representation and warranty contained in (A)
Section 3.2 of the Credit Agreement shall be deemed modified to change the date
referred to therein from December 31, 1999 to September 17, 2001 and (B) Section
3.18 of the Credit Agreement shall be deemed modified to change the last
sentence thereof to replace the word "There" in the beginning of such sentence
with "Since September 17, 2001, there".

                  10.      Conditions to Effectiveness. This Amendment shall
become effective on and as of the date that:

                  (a)      the Administrative Agent shall have received
counterparts of this Amendment, duly executed and delivered by a duly authorized
officer of the Borrower;

                  (b)      the Administrative Agent shall have received executed
Lender Consent Letters, substantially in the form of Exhibit B hereto, from
Lenders whose consent is required pursuant to Section 9.1 of the Credit
Agreement;

                  (c)      the Administrative Agent shall have received, for the
benefit of each Lender whose executed Lender Consent Letter is delivered to the
Administrative Agent on or before 3:00 p.m., New York time, on Friday, September
28, 2001, an amendment fee in an amount equal to .25% of the aggregate amount of
Term Loans of such Lender outstanding on the date hereof;
<PAGE>

                                                                               4


                  (d)      the Administrative Agent shall have received an
executed Acknowledgment and Consent, in the form set forth at the end of this
Amendment, from each Loan Party other than the Borrower;

                  (e)      the Administrative Agent shall have received an
executed certificate of an officer of the Borrower in form satisfactory to the
Administrative Agent as to (i) the accuracy of the representations and
warranties set forth in Section 9 of this Amendment, in Section 3 of the Credit
Agreement after giving effect to this Amendment and in the other Loan Documents
(provided, that purposes of such certificate the representation and warranty
contained in (A) Section 3.2 of the Credit Agreement shall be deemed modified to
change the date referred to therein from December 31, 1999 to September 17, 2001
and (B) Section 3.18 of the Credit Agreement shall be deemed modified to change
the last sentence thereof to replace the word "There" in the beginning of such
sentence with "Since September 17, 2001, there"), (ii) the absence of any
Default or Event of Default after giving effect to this Amendment, and (iii)
such other customary matters as the Administrative Agent may reasonably request;
and

                  (f)      the Administrative Agent shall have received executed
counterparts of the Interim Loan Facility Extension.

                  11.      Limited Consent and Amendment. Except as expressly
amended herein, the Credit Agreement shall continue to be, and shall remain, in
full force and effect. This Amendment shall not be deemed to be a waiver of, or
consent to, or a modification or amendment of, any other term or condition of
the Credit Agreement or any other Loan Document or to prejudice any other right
or rights which the Lenders may now have or may have in the future under or in
connection with the Credit Agreement or any of the instruments or agreements
referred to therein, as the same may be amended from time to time.

                  12.      Counterparts. This Amendment may be executed by one
or more of the parties hereto in any number of separate counterparts (which may
include counterparts delivered by facsimile transmission) and all of said
counterparts taken together shall be deemed to constitute one and the same
instrument.

                  13.      GOVERNING LAW. THIS AMENDMENT SHALL BE GOVERNED BY,
AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW
YORK.
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                                                                               5


                  IN WITNESS WHEREOF, the parties hereto have caused this
Amendment to be executed and delivered by their respective duly authorized
officers as of the date first above written.

                                       ANC RENTAL CORPORATION


                                       By: /s/ Howard D. Schwartz
                                           -------------------------------------
                                             Name:  Howard D. Schwartz
                                             Title: Sr. Vice President &
                                                    Secretary


                                       LEHMAN COMMERCIAL PAPER INC.,
                                        as Administrative Agent


                                       By: /s/ G. Andrew Keith
                                           -------------------------------------
                                             Name:  G. Andrew Keith
                                             Title: Authorized Signatory
<PAGE>

                                                                               6

                           ACKNOWLEDGMENT AND CONSENT

                  Each of the undersigned parties to the Guarantee and
Collateral Agreement, dated as of June 30, 2000 and as amended, supplemented or
otherwise modified from time to time, made by the undersigned in favor of Lehman
Commercial Paper Inc., as Administrative Agent, for the benefit of the Secured
Parties, hereby (a) consents to the transactions contemplated by the foregoing
Amendment to the Credit Agreement and (b) acknowledges and agrees that the
guarantees and grants of security interests contained in the Guarantee and
Collateral Agreement and in the other Security Documents are, and shall remain,
in full force and effect after giving effect to such Amendment and all prior
modifications to the Credit Agreement.

                       ALAMO RENT-A-CAR (CANADA), INC.
                       LIABILITY MANAGEMENT COMPANIES
                       HOLDING, INC.
                       NATIONAL CAR RENTAL LICENSING, INC.
                       NATIONAL CAR RENTAL SYSTEM, INC.
                       REPUBLIC GUY SALMON PARTNER, INC.
                       REPUBLIC INDUSTRIES AUTOMOTIVE
                       RENTAL GROUP (BELGIUM) INC.
                       SPIRIT RENT-A-CAR, INC.
                       ALAMO RENT-A-CAR MANAGEMENT, LP
                            By:  ARC-GP, Inc., its general partner
                       ANC COLLECTOR CORPORATION
                       ANC FINANCIAL, LP
                            By:  ANC Financial GP Corporation, its general
                                 partner
                       ARC-GP, INC.
                       ARC-TM, INC.
                       NCR AFFILIATE SERVICER, INC.
                       NCRAS MANAGEMENT, LP
                            By:  NCRAS-GP, Inc., its general partner
                       NCRAS-GP, INC.
                       SRAC MANAGEMENT, LP
                            By:  SRAC-GP, Inc., its general partner
                       SRAC-GP, INC.
                       SRAC-TM, INC.

                       By: /s/ Leland F. Wilson
                           ----------------------------------------
                             Name:  Leland F. Wilson
                             Title: Vice President & Treasurer

                       ALAMO RENT-A-CAR, LLC

                       By: /s/ Kathleen W. Kyle
                           ----------------------------------------
                             Name:  Kathleen W. Kyle
                             Title: Sr. Vice President & Treasurer
<PAGE>



                       ANC FINANCIAL CORPORATION
                       ANC FINANCIAL PROPERTIES LLC
                       ANC INFORMATION TECHNOLOGY HOLDING, INC.
                       ANC INFORMATION TECHNOLOGY, INC.
                       ANC INFORMATION TECHNOLOGY, L.P.
                            By:  ANC INFORMATION TECHNOLOGY,
                                 INC., its general partner
                       ANC IT COLLECTOR CORPORATION
                       ARC-TM PROPERTIES LLC
                       NCR AFFILIATE SERVICER PROPERTIES, LLC

                       By: /s/ Leland F. Wilson
                           ----------------------------------------
                             Name:  Leland F. Wilson
                             Title: Vice President & Treasurer
<PAGE>

                                                                       EXHIBIT A


                             INTERIM LOAN EXTENSION
<PAGE>

                                                                       EXHIBIT B


                              LENDER CONSENT LETTER

                             ANC RENTAL CORPORATION
                      AMENDED AND RESTATED CREDIT AGREEMENT
                            DATED AS OF JUNE 30, 2000

To:           Lehman Commercial Paper Inc.
              3 World Financial Center
              New York, New York  10285

Ladies and Gentlemen:

                  Reference is made to the Amended and Restated Credit
Agreement, dated as of June 30, 2000 (as heretofore amended, supplemented or
otherwise modified, the "Credit Agreement"), among ANC RENTAL CORPORATION, a
Delaware corporation (the "Borrower"), the Lenders parties thereto, LEHMAN
COMMERCIAL PAPER INC., as Syndication Agent and as Administrative Agent, and
others. Unless otherwise defined herein, capitalized terms used herein and
defined in the Credit Agreement are used herein as therein defined.

                  The Borrower has requested that the Lenders consent to amend
the Credit Agreement on the terms described in the Amendment to which a form of
this Lender Consent Letter is attached as Exhibit A (the "Amendment").

                  Pursuant to Section 9.1 of the Credit Agreement, the
undersigned Lender hereby consents to the execution by the Agents of the
Amendment.

                                        Very truly yours,


                                        ---------------------------
                                        (NAME OF LENDER)


                                        By:
                                           -------------------------------------
                                              Name:
                                              Title:


Dated as of ____________ __, 2001