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                                                                     EXHIBIT 4.2

                                 AMENDMENT NO. 1

                                     TO THE

               FOURTH AMENDED AND RESTATED STOCKHOLDERS' AGREEMENT

                                      AMONG

                           DEALERTRACK HOLDINGS, INC.

                                     AND THE

                         STOCKHOLDERS IDENTIFIED HEREIN

                               AS OF MAY 26, 2005

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      AMENDMENT NO. 1 TO THE FOURTH AMENDED AND RESTATED STOCKHOLDERS' AGREEMENT
among:

      I. DEALERTRACK HOLDINGS, INC., a Delaware corporation (the "Corporation");

      II. the STOCKHOLDERS of the Corporation identified on Annex I of the
Agreement (each, a "Stockholder" and, collectively, the "Stockholders"); and

      III. DEALERTRACK, INC., WEBALG, INC., CREDIT ONLINE, INC., DEALERACCESS
INC., DEALERTRACK AFTERMARKET SERVICES, INC. and CHROME SYSTEMS, INC., each a
Delaware corporation and a wholly-owned subsidiary of the Corporation
(collectively the "US Subsidiaries"), and DEALERACCESS CANADA INC., a Canadian
corporation and a wholly-owned subsidiary of dealerAccess Inc. (collectively
with the Corporation, Stockholders and US Subsidiaries, the "Parties").

            WHEREAS, the Parties hereto have entered into the Fourth Amended and
Restated Stockholders' Agreement, dated as of March 19, 2003 (the "Agreement";
capitalized terms used but not defined herein shall have the meanings assigned
to them in the Agreement);

            WHEREAS, pursuant to Section 20 of the Agreement, the Agreement may
be modified by an instrument in writing signed by the Corporation and the
Requisite Designated Preferred Stockholders (as defined in the Certificate); and

            WHEREAS, it is deemed to be in the best interest of the Corporation
and the Stockholders that the Agreement be amended and, to that end, the
Corporation and the Stockholders hereby set forth their agreement, as of May 26,
2005, with respect to this Amendment No. 1 (the "Amendment") to the Agreement.

            NOW, THEREFORE, in consideration of the promises and of the mutual
covenants and obligations hereinafter set forth, the Parties hereto hereby agree
as follows:

            SECTION 1. AMENDMENT TO SECTION 1.

                        The Parties hereto agree that the following definition
shall be inserted into Section 1 of the Agreement immediately following the
definition of "DGCL":

            ""Director Designator" shall have the meaning set forth in Section
10(f) hereof."

            SECTION 2. AMENDMENT TO SECTION 10.

            The Parties hereto agree that Section 10 of the Agreement shall be
amended and restated in its entirety as follows:

                  "SECTION 10. ELECTION OF DIRECTORS; VOTING.

                  (a) The number of directors constituting the Board, as fixed
      from time to time by the Board in accordance with the Certificate and the
      By-Laws, shall be not less

Amendment No. 1 to Fourth Amended and Restated
Stockholders' Agreement

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      than three (3) nor more than eleven (11). The number of directors
      constituting the boards of directors of each Subsidiary shall correspond
      to the number of directors on the Board and each member of the Board shall
      at all times serve as a director on the board of directors of each
      Subsidiary, except dealerAccess Canada Inc. Any vacancy on the Board or on
      the board of directors of any Subsidiary from time to time shall not be
      considered to be a decrease in the number of directors constituting such
      board. At each annual meeting of the holders of any class of Stock, and at
      each special meeting of the holders of any class of Stock called for the
      purpose of electing directors of the Corporation, and at any time at which
      holders of any class of Stock shall have the right to, or shall, vote for
      or consent in writing to the election of directors of the Corporation,
      then, and in each such event, the Stockholders shall vote all of the
      shares of the Stock owned by them or their Affiliates, and their
      respective transferees shall so vote for, or consent in writing with
      respect to such shares in favor of, the election of a Board of the
      Corporation constituted as follows:

                  (i) two (2) directors who shall be designated and approved by
            J.P. Morgan (each a "J.P. Morgan Director");

                  (ii) one (1) director who shall be designated and approved by
            Wells Fargo (the "WF Director"); provided that Wells Fargo, together
            with its Affiliates, and other members of its Group, holds either
            (A) equity securities of the Corporation representing at least five
            (5%) percent of the voting power thereof (determined on a Fully
            Diluted Basis) or (B) at least seventy-five (75%) percent of the
            Stock of the Corporation held by it as of the Closing Date (as
            adjusted for stock splits, stock dividends and the like);

                  (iii) one (1) director who shall be designated and approved by
            AmeriCredit (the "AmeriCredit Director"), provided that AmeriCredit,
            together with its Affiliates, and other members of its Group, holds
            either (A) equity securities of the Corporation representing at
            least five (5%) percent of the voting power thereof (determined on a
            Fully Diluted Basis) or (B) at least seventy-five (75%) percent of
            the Stock of the Corporation held by it as of the Closing Date (as
            adjusted for stock splits, stock dividends and the like);

                  (iv) one (1) director who shall be designated and approved by
            Capital One (the "Capital One Director"); provided that Capital One,
            together with its Affiliates, and other members of its Group, holds
            either (A) equity securities of the Corporation representing at
            least five (5%) percent of the voting power thereof (determined on a
            Fully Diluted Basis) or (B) at least seventy-five (75%) percent of
            the Stock of the Corporation held by it as of the Closing Date (as
            adjusted for stock splits, stock dividends and the like);

                  (v) one (1) director who shall be designated and approved by
            WFS (the "WFS Director"); provided that WFS, together with its
            Affiliates, and other members of its Group, holds either (A) equity
            securities of the Corporation representing at least five (5%)
            percent of the voting power thereof (determined on a Fully Diluted
            Basis) or (B) at least seventy-five (75%) percent of the Stock of

Amendment No. 1 to Fourth Amended and Restated
Stockholders' Agreement

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            the Corporation held by it as of the Closing Date (as adjusted for
            stock splits, stock dividends and the like);

                  (vi) one (1) director who shall be designated and approved by
            GRP (the "GRP Director"); provided that GRP, together with its
            Affiliates, and other members of its Group, holds either (A) equity
            securities of the Corporation representing at least five (5%)
            percent of the voting power thereof (determined on a Fully Diluted
            Basis) or (B) at least seventy-five (75%) percent of the Stock of
            the Corporation held by it as of the Closing Date (as adjusted for
            stock splits, stock dividends and the like);

                  (vii) one (1) director who shall be designated and approved by
            The First American Corporation ("FAC") (the "FAC Director");
            provided that FAC, together with its Affiliates, and other members
            of its Group, holds either (A) equity securities of the Corporation
            representing at least five (5%) percent of the voting power thereof
            (determined on a Fully Diluted Basis) or (B) at least seventy-five
            (75%) percent of the Stock of the Corporation held by CMSI as of the
            Closing Date (as adjusted for stock splits, stock dividends and the
            like);

                  (viii) one (1) director who shall be the Chief Executive
            Officer of the Corporation; and

                  (ix) two (2) directors who shall not be officers of the
            Corporation and shall each be designated and approved by
            AmeriCredit, J.P. Morgan and Wells Fargo, acting jointly; provided
            however, that Capital One, FAC, GRP and WFS, acting jointly, may
            veto any individual proposed as a director under this Section
            10(a)(viii) within 14 calendar days of receipt of the name and
            resume of such proposed director, except that Capital One, FAC, WFS
            and GRP agree not to unreasonably veto any such individual who is
            designated by AmeriCredit, J.P. Morgan and Wells Fargo hereunder;

      provided, however, that if a Director Designator chooses not to exercise
      its right pursuant to Section 10(a) to designate a director, such Director
      Designator's rights under Section 10(a) shall continue in full force and
      effect.

                  (b) Each respective party designating directors pursuant to
      Section 10(a) shall have the right (i) to have such director serve as
      director until his or her successor is duly elected and qualified, (ii) to
      designate each such successor so long as such party has the power to
      designate such director pursuant to Section 10(a) above, (iii) to propose
      the removal from the Board of any director nominated by such party
      pursuant to Section 10(a) and (iv) to propose the removal from the Board
      of a director nominated by another party in the event that such other
      party ceases to possess the power to nominate such director as a result of
      the application of any of the provisions of Section 10(a) above. The
      Stockholders shall vote their shares (i) to remove any director whose
      removal is required pursuant to clause (iii) or (iv) of the preceding
      sentence by the party or Parties with the power to designate such director
      pursuant to Section 10(a) and (ii) to fill any vacancy created by the
      removal, resignation or death of a director, in each case

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Stockholders' Agreement

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      for the election of a new director designated and approved, if approval is
      required, in accordance with the provisions of this Section 10.

                  (c) The members of each committee of the Board shall be
      selected by the Board and shall include (i) one (1) J.P. Morgan Director
      (if a J.P. Morgan Director is so designated pursuant to Section 10(a)(i))
      and (ii) such other director(s) selected by the Board. The Corporation and
      the Board shall ensure that, to the extent that directors are designated
      pursuant to Section 10(a)(ii)-(vii), the AmeriCredit Director, the Capital
      One Director, the FAC Director, the WF Director, the WFS Director and the
      GRP Director are each members of the same number of committees as is
      reasonably possible. The Corporation and Board shall also ensure that no
      Stockholder has more than one representative as a member on a certain
      committee. In the event that AmeriCredit, Capital One, FAC, Wells Fargo,
      WFS or GRP is not a member of a particular committee, AmeriCredit, Capital
      One, FAC, Wells Fargo, WFS or GRP, as the case may be, shall have the
      right to designate one individual as a non-voting observer (each a
      "Committee Observer") to such committee. The Corporation shall give each
      Committee Observer and the ALG Observer (as defined below) the same
      notice, information and documentation with respect to committee meetings
      as the members of such committees receive; provided, however, that each
      Committee Observer and the ALG Observer shall agree to hold all
      information so provided in confidence and trust; provided further,
      however, that the Corporation reserves the right to withhold any
      information and to exclude any Committee Observer and or the ALG Observer
      from any meeting or portion thereof, without excluding any other Committee
      Observer and or the ALG Observer, if the Board determines in good faith
      that access to such information or attendance at such meeting would
      adversely affect the attorney-client privilege between the Corporation and
      its counsel.

                  (d) ALG shall have the right to designate one individual as a
      non-voting observer to the Board and to any committees of the Board (the
      "ALG Observer"). All other Investors shall have the right to designate one
      individual as a non-voting observer to the Board, subject to the ability
      of the Board to determine that no Investor (other than ALG) shall have
      such right (each a "Board Observer"). The Corporation shall give the ALG
      Observer and each Board Observer the same notice, information and
      documentation with respect to Board meetings as the members receive;
      provided, however, that the ALG Observer and the Board Observers, if any,
      shall agree to hold all information so provided in confidence and trust;
      provided further, however, that the Corporation reserves the right to
      withhold any information and to exclude the ALG Observer, without
      excluding any Board Observer or the ALG Observer, as the case may be, from
      any meeting or portion thereof if the Board determines in good faith that
      access to such information or attendance at such meeting would adversely
      affect the attorney-client privilege between the Corporation and its
      counsel.

                  (e) The Stockholders shall cause the Corporation to appoint,
      replace and remove the directors of each of its Subsidiaries, except
      dealerAccess Canada Inc., and each of DealerTrack, Inc., webalg, inc.,
      Credit Online, Inc., DealerTrack Aftermarket Services, Inc., dealerAccess
      Inc. and Chrome Systems, Inc. hereby agrees to such appointment,
      replacement and removal, in accordance with the terms of this Section 10
      as

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Stockholders' Agreement

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      applied mutatis mutandis to such Subsidiaries, such that at all times the
      Board of the Corporation and of each Subsidiary of the Corporation, except
      dealerAccess Canada Inc., shall consist of the same individuals.

                  (f) Each respective party designating directors pursuant to
      Section 10(a) (each, a "Director Designator") shall cause the director(s)
      designated by such party to agree to resolve that as of the date of this
      Amendment, the Board shall be fixed at five (5); provided, however, that
      if at any time during the term of this Agreement any Director Designator
      chooses to exercise its right to designate a director pursuant to Section
      10(a), then (i) all of the Director Designators shall cause the
      director(s) designated by each of them to agree to resolve to increase the
      size of the Board accordingly to accommodate such additional designee(s)
      and (ii) the Stockholders shall vote all of the shares of the Stock owned
      by them or their Affiliates, and their respective transferees shall so
      vote for, or consent in writing with respect to such shares in favor of,
      the election of the additional designee(s)."

            SECTION 3. HEADINGS.

            The headings of the sections of this Amendment have been inserted
for convenience of reference only and shall not be deemed to be a part of this
Amendment.

            SECTION 4. NOUNS AND PRONOUNS.

            Whenever the context may require, any pronouns used herein shall
include the corresponding masculine, feminine or neuter forms, and the singular
form of names and pronouns shall include the plural and vice versa.

            SECTION 5. ENTIRE AGREEMENT.

            Except as otherwise expressly set forth herein, this Amendment
embodies the complete agreement and understanding among the Parties hereto with
respect to the subject matter hereof and supersedes and preempts any prior
understandings or representations by or among the Parties, written or oral,
which may have related to the subject matter hereof in any way.

            SECTION 6. COUNTERPARTS.

            This Amendment may be executed in any number of counterparts, and
each such counterpart hereof shall be deemed to be an original instrument, but
all such counterparts together shall constitute but one agreement.

                                     * * * *

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Stockholders' Agreement

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            IN WITNESS WHEREOF, the Parties hereto have executed this Amendment
on the date first above written.

                             "CORPORATION"
                             DEALERTRACK HOLDINGS, INC.

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

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Stockholders' Agreement

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                             "STOCKHOLDERS"

                             ACF INVESTMENT CORP.

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

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Stockholders' Agreement

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                             AUTOMOTIVE LEASE GUIDE (ALG), LLC

                             By: _______________________________________________
                                   Name:
                                   Title:

Amendment No. 1 to Fourth Amended and Restated
Stockholders' Agreement

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                             J.P. MORGAN PARTNERS (23A SBIC), LLC

                             By: J.P. Morgan Partners (23A SBIC Manager), Inc.,
                                 its Managing Member

                             By: _______________________________________________
                                   Name:
                                   Title:

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Stockholders' Agreement

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                             WELLS FARGO SMALL BUSINESS INVESTMENT COMPANY, INC.

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

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

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Stockholders' Agreement

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                             CAPITAL ONE AUTO FINANCE, INC.

                             By: _______________________________________________
                                   Name:
                                   Title:

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Stockholders' Agreement

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                             FIRST AMERICAN CREDIT MANAGEMENT SOLUTIONS, INC.

                             By: _______________________________________________
                                   Name:
                                   Title:

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                             WELLS FARGO FINANCIAL, INC.

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

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                             WFS WEB INVESTMENTS

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

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                             GRP II, L.P., a Delaware limited partnership

                             By: GRPVC, L.P., its General Partner

                             By: GRP Management Services Corp., a
                                 Delaware corporation, its General Partner

                             By: _______________________________________________
                                   Name:
                                   Title:

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Stockholders' Agreement

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                             GRP II PARTNERS, L.P., a Delaware limited
                                 partnership

                             By: GRPVC, L.P., its General Partner

                             By: GRP Management Services Corp., a
                                 Delaware corporation, its General Partner

                             By: _______________________________________________
                                   Name:
                                   Title:

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Stockholders' Agreement

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                             GRP II INVESTORS, L.P., a Delaware limited
                                 partnership

                             By: Merchant Capital, Inc., its General Partner

                             By: _______________________________________________
                                   Name:
                                   Title:

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Stockholders' Agreement

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                             ---------------------------------------------------
                                    Mary Cirillo-Goldberg

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Stockholders' Agreement

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                             ---------------------------------------------------
                                    Mark F. O'Neil

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Stockholders' Agreement

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                             ---------------------------------------------------
                                    Robert Cox

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Stockholders' Agreement

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                             ---------------------------------------------------
                                    Vincent Passione

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Stockholders' Agreement

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                             ---------------------------------------------------
                             Eric D. Jacobs

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                             DEALERTRACK, INC.

                             By:
                                 -----------------------------------------------
                                     Name:  Mark F. O'Neil
                                     Title: Chief Executive Officer & President

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Stockholders' Agreement

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                             WEBALG, INC.

                             By:
                                 -----------------------------------------------
                                    Name:  Mark F. O'Neil
                                    Title: Chief Executive Officer & President

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Stockholders' Agreement

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                             CREDIT ONLINE, INC.

                             By: _______________________________________________
                                   Name:
                                   Title:

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Stockholders' Agreement

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                             DEALERTRACK AFTERMARKET SERVICES, INC.

                             By: _______________________________________________
                                   Name:
                                   Title:

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Stockholders' Agreement

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                             DEALERACCESS INC.

                             By: _______________________________________________
                                   Name:
                                   Title:

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Stockholders' Agreement

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                             DEALERACCESS CANADA INC.

                             By: _______________________________________________
                                   Name:
                                   Title:

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Stockholders' Agreement

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                             CHROME SYSTEMS, INC.

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

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Stockholders' Agreement

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