<PAGE>

                                                                EXHIBIT 10.17(A)
                               FIRST AMENDMENT TO

                     VOTING AGREEMENT AND IRREVOCABLE PROXY

     The undersigned parties to that certain Voting Agreement and Irrevocable
Proxy (the "Agreement"), dated as of August 29, 2003, by and among Keystone
Automotive Holdings, Inc., a Delaware corporation, Keystone Automotive
Operations, Inc., a Pennsylvania corporation, and the Shareholders (as defined
therein) desire to amend, as of October 15, 2003, the Agreement in the manner
set forth herein. Capitalized terms used herein but not otherwise defined herein
shall have the respective meanings set forth in the Agreement.

     1.   Amendment.

          (a)  The first sentence of Section 1(a) of the Agreement is hereby
amended and restated to read in its entirety as follows:

          "Each shareholder hereby agrees that during the period
          commencing on the date hereof and continuing until this
          provision terminates pursuant to Section 7 hereof, at any
          meeting of shareholders of the Company, however called, or
          in connection with any written consent of the shareholders
          of the Company, such Shareholder shall vote (or cause to be
          voted) the Shares held of record or beneficially owned by
          such Shareholder, whether heretofore owned or hereafter
          acquired, and shall exercise (or cause to be exercised) all
          consensual rights attendant thereto (i) in favor of approval
          of the Merger Agreement and the transactions contemplated
          thereby (including the Merger) and any actions required in
          furtherance thereof and hereof; (ii) against any action or
          agreement that would result in a breach in any respect of
          any covenant, representation or warranty or any other
          obligation or agreement of the Company under the Merger
          Agreement; and (iii) except as otherwise contemplated or
          permitted by the Merger Agreement, against the following
          actions (other than the Merger and the transactions
          contemplated by the Merger Agreement): (A) any Alternative
          Transaction; (B) a sale, lease or transfer of a material
          amount of assets of the Company, or a reorganization,
          recapitalization, dissolution or liquidation of the Company;
          (C) any change in a majority of the persons who constitute
          the board of directors of the Company or a change in
          management of the Company; (D) any amendment of the
          Company's articles of incorporation or by-laws; or (E) any
          other action which is intended, or could reasonably be
          expected, to impede, interfere with, delay, postpone, or
          adversely affect the

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          Merger and the transactions contemplated by this Agreement
          and the Merger Agreement."

          (b)  Section 6(a) of the Agreement is hereby amended and restated to
read in its entirety as follows:

          "During the period commencing on the date hereof and
          continuing until this provision terminates pursuant to
          Section 7 hereof, each Shareholder hereby irrevocably
          appoints the Holder Representative or any individual
          designated by the Holder Representative as such
          Shareholder's agent, attorney-in-fact and proxy (with full
          power of substitution), for in the name, place and stead of
          such Shareholder, to vote (or cause to be voted) the Shares
          held of record or beneficially owned by such Shareholder,
          whether issued, heretofore owned or hereafter acquired, or
          grant a consent or approval in respect of such Shares, at
          any meeting of Shareholders of the Company or at any
          adjournment thereof or in any other circumstances upon which
          his, her or its vote, consent or other approval is sought:
          (i) in favor of approval of the Merger Agreement and any
          actions required in furtherance thereof and hereof;
          provided, however, that if the Holder Representative fails
          to vote the Shares in favor of the approval of the Merger
          Agreement or any actions required in furtherance thereof or
          hereof, each Shareholder shall be deemed to have appointed
          the Acquiror as such Shareholders' agent, attorney-in-fact
          and proxy (with full power of substitution), for in the
          name, place and stead of such Shareholder, to vote (or cause
          to be voted) the Shares held of record or beneficially owned
          by such Shareholder in favor of the approval of the Merger
          Agreement and any actions required in furtherance thereof or
          hereof; (ii) against any action or agreement that would
          result in a breach in any respect of any covenant,
          representation or warranty or any other obligation or
          agreement of the Company under the Merger Agreement; and
          (iii) except as contemplated or permitted by the Merger
          Agreement, against the following actions (other than the
          Merger and the transactions contemplated by the Merger
          Agreement): (A) any extraordinary corporate transaction,
          such as a merger, consolidation or other business
          combination involving the Company; (B) a sale, lease or
          transfer of a material amount of asset of the Company, or a
          reorganization or other business combination involving the
          Company; (C) any change in a majority of the persons who
          constitute the board of directors of the Company; (D) any
          amendment to the

                                      -2-

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          Company's article or incorporation or by-laws; or (E) any
          other action which is intended, or could reasonably be
          expected, to impede, interfere with, delay, postpone, or
          adversely affect the Merger and the transactions
          contemplated by this Agreement and the Merger Agreement."

     2.   Effectiveness of Amendments. The amendments to the Agreement
contemplated hereby shall become effective as of the date first above written.

     3.   Confirmation of Agreement. Except as set forth in Section 1 of this
Amendment, the terms, conditions and agreements set forth in the Agreement are
hereby ratified and confirmed and shall continue in full force and effect.

     4.   Governing Law. THIS AMENDMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE COMMONWEALTH OF PENNSYLVANIA.

     5.   Counterparts. This Amendment may be executed (including execution by
facsimile) in any number of counterparts, each of which shall be deemed an
original and all of which taken together shall constitute one and the same
instrument.

                                   * * * * * *

                                       -3-

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     IN WITNESS WHEREOF, the parties hereto have caused this First Amendment to
Voting Agreement and Irrevocable Proxy to be duly executed as of the date first
written above.

                                        KEYSTONE AUTOMOTIVE HOLDINGS, INC.


                                        By:  /s/ David Gross-COH
                                             -----------------------------------
                                             Name: David Gross-COH
                                             Title: Vice President

                                        LAGE LLC


                                        By:  /s/ MICHAEL I. KLEIN
                                             -----------------------------------
                                             Name: MICHAEL I. KLEIN
                                             Title: PRESIDENT


                                        KEYSTONE AUTOMOTIVE OPERATIONS, INC..


                                        By:  /s/ ROBERT S. VOR BROKER
                                             -----------------------------------
                                             Name: ROBERT S. VOR BROKER
                                             Title: PRESIDENT


                      [Shareholders Signature Pages Follow]

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                          Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Joseph Amato
                                        ----------------------------------------
                                        Signature

                                        Joseph Amato
                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity




<PAGE>

                          Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Peter Amato
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Peter Amato
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity

<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Philip Avvisato
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Philip Avvisato
                                        ----------------------------------------
                                        Signature

                                        Philip Avvisato
                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity


<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Bryant Bynum
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Bryant Bynum
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity

<PAGE>


                          Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        James Chebalo
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ James Chebalo
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity



<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        R. Randolph Devening
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ R. Randolph Devening
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity



<PAGE>

                          Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Ronald E Elmodist
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Ronald E Elmodist
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity



<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Anthony Foudiani
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Anthony Foudiani
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity

<PAGE>

                          Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Patrick Judge
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Patrick Judge
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity


<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Richard Kovalick
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Richard Kovalick
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity

<PAGE>


                          Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        George Lathouris
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ George Lathouris
                                        ----------------------------------------
                                        Signature

                                        George Lathouris
                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity


<PAGE>
Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Scott Merlis
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Scott Merlis
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity


<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Lawrence Montante
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Lawrence Montante
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity


<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Richard Piontkowski
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Richard Piontkowski
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity


<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Victor Pompino
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Victor Pompino
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity

<PAGE>


                          Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:


                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Leonard Ross
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity


<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        James Ruby
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ James Ruby
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity


<PAGE>

                          Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Daniel Thomas Jr
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Daniel Thomas Jr
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity


<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Robert S. Vor Broker
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Robert S. Vor Broker
                                        ----------------------------------------
                                        Signature


                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity



<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy and, by
execution hereof, hereby agrees to be bound by the terms and conditions thereof
as a Shareholder.

                                        Shareholder:

                                        ADVENT GLOBAL GECC III LP
                                        By: Advent Global Management Limited
                                            Partnership, its general partner
                                        By: Advent International Limited
                                            Partnership, its general partner
                                        By: Advent International Corporation,
                                            its general partner

                                        By: /s/ Robert E. Taylor, Jr.
                                        ----------------------------------------
                                        Name:   Robert E. Taylor, Jr.
                                        Title:  Vice President

                                        GLOBAL PRIVATE EQUITY III LP
                                        ADVENT PPGM GLOBAL LP
                                        By: Advent International Limited
                                            Partnership, its general partner
                                        By: Advent International Corporation,
                                            its general partner

                                        By: /s/ Robert E. Taylor, Jr.
                                        ----------------------------------------
                                        Name:   Robert E. Taylor,Jr.
                                        Title:  Vice President

                                        ADVENT PARTNERS GPE III LP
                                        ADVENT PARTNERS (NA) GPE III LP
                                        ADVENT PARTNERS LP
                                        By: Advent International Corporation,
                                            its general partner

                                        By: /s/ Robert E. Taylor, Jr.
                                        ----------------------------------------
                                        Name:   Robert E. Taylor, Jr.
                                        Title:  Vice President



<PAGE>

                         Shareholder Signature Page to

            First Amendment to Voting Agreement and Irrevocable Proxy

          The undersigned hereby confirms that it has received and reviewed a
copy of the First Amendment to Voting Agreement and Irrevocable Proxy (the
"First Amendment") and, by execution hereof, hereby agrees to be bound by the
terms of the Agreement as amended by the First Amendment.

                                        Shareholder:

                                        Littlejohn Partners II, L.P.
                                        ----------------------------------------
                                        [Name of Shareholder]

                                        /s/ Michael I. Klein
                                        ----------------------------------------
                                        Signature

                                        Michael I. Klein
                                        ----------------------------------------
                                        Print Name of Signatory


                                        ----------------------------------------
                                        Print Title of Signatory if
                                        signing on behalf of an Entity