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                                                                    EXHIBIT 3.11

                          CERTIFICATE OF INCORPORATION

                                       OF

                               AUTO-AID MFG. CORP.

               Under Section 402 of the Business Corporation Law.

      The undersigned, for the purpose of forming a corporation pursuant to
Section 402 of the Business Corporation Law of the State of New York; does
hereby certify and set forth:

      FIRST: The name of the corporation is AUTO-AID MFG. CORP.

      SECOND: The purposes, for which the corporation is formed, are:

      (1) To manufacture, buy, sell, distribute, job, to be a franchise dealer
licensee, import, export and otherwise deal in automobile supplies and equipment
of every kind and description, and other related and unrelated products at
wholesale and at retail and as principal and agent.

      (2) To create, manufacture, contract for, buy, sell, import, export,
distribute, job and generally deal in and with, whether at wholesale or retail,
and as principal, agent, broker, factor, commission merchant, licensor, licensee
or otherwise, any and all kinds of automobile supplies and equipment and in
connection therewith or independent thereof, to establish and maintain, by any
manner or means, buying offices, distribution centers, specialty and other
shops, stores, mail-order establishments, concessions, leased departments, and
any and all other departments, sites and locations necessary, convenient or
useful in the furtherance of any business of the corporation.

      (3) To manufacture, prepare, buy, sell, deal in, trade in, lease, import
and export, paint, repair, restore and recondition automobiles, trucks,
trailers, motorcycles,


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tractors and motor vehicles of every description, and all parts, accessories and
supplies thereof, including armatures, axles, batteries, bearings, bodies,
brakes, brake linings, bumpers, carburetors, chassis, electrical service,
fenders, gears, glass, headlights, side, tail and stop lights, horns, ignition
systems, lamps, locks, motors, assembled and all parts thereof, pistons, piston
rings, radiators, starters, shock absorbers, spark plugs, springs, speedometers,
tires, wheels, tops, upholstery, panels and dashboards, heaters, generators,
drive shafts, differentials, windshields, windshield wipers, and all hardware,
tools and implements for motor vehicles of every kind and make.

      (4) To acquire by purchase, subscription, underwriting or otherwise, and
to own, hold for investment, or otherwise, and to use, sell, assign, transfer,
mortgage, pledge, exchange, or otherwise dispose of real and personal property
of every sort and description and wheresoever situated, including shares of
stock, bonds, debentures, notes, scrip, securities, evidences of indebtedness,
contracts or obligations of any corporation or association, whether domestic or
foreign, or of any firm or individual or of the United States or any state,
territory or dependency of the United States or any foreign country, or any
municipality or local authority within or without the United States, and also to
issue in exchange therefor, stocks, bonds or other securities or evidences of
indebtedness of this corporation, and, while the owner or holder of any such
property, to receive, collect and dispose of the interest, dividends and income
on or from such property and to possess and exercise in respect thereto all of
the rights, powers and privileges of ownership, including all voting powers
thereon.

      (5) To construct, build, purchase, lease or otherwise acquire, equip,
hold, own, improve, develop, manage, maintain, control, operate, lease,
mortgage, create liens upon, sell, convey or otherwise dispose of and turn to
account, any and all plants, machinery, works, implements and things or
property, real and personal, of every kind and description, incidental to,
connected with, or suitable, necessary or convenient for any of the purposes
enumerated herein, including all or any part or parts of the properties, assets,
business and good will of any persons, firms, associations or corporations.

      (6) The powers, rights and privileges provided in this certificate are not
to be deemed to be in limitation of similar, other or additional powers, rights
and


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privileges granted or permitted to a corporation by the Business Corporation
Law, it being intended that this corporation shall have all the rights, powers
and privileges granted or permitted to a corporation by such statute.

      THIRD: The office of the corporation is to be located in the City of New
York, County of Kings, State of New York.

      FOURTH: The aggregate number of shares which the corporation shall have
the authority to issue is Two Hundred (200), all of which shall be without par
value.

      FIFTH: The Secretary of State is designated as agent of the corporation
upon whom process against it may be served. The post office address to which the
Secretary of State shall mail a copy of any process against the corporation
served upon him is:

                              476 Jefferson Street
                              Brooklyn, New York

      The undersigned incorporator is of the age of twenty one years or over.

      IN WITNESS WHEREOF, this certificate has been subscribed to this 19th day
of September, 1972, by the undersigned, who affirms that the statements made
herein are true under the penalties of perjury.


                                        /s/ Gerald Weinberg
                                        ----------------------------------------
                                        GERALD WEINBERG
                                        90 State Street
                                        Albany, New York


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        Certificate of Amendment of the Certificate of Incorporation of

                               AUTO AID MFG. CORP.

                under Section 805 of the Business Corporation Law

IT IS HEREBY CERTIFIED THAT:

      (1)   The name of the corporation is

                        AUTO AID MFG. CORP.

      (2)   The certificate of incorporation was filed by the department of
            state on the twentieth (20) day of September 1972.

      (3)   The certificate of incorporation of this corporation is hereby
            amended to effect the following change*

            The name of the corporation is changed to MEDO INDUSTRIES, INC.


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      (4)   The amendment to the certificate of incorporation was authorized:

                  *     at a meeting of shareholders by vote of a majority of
                        all the outstanding shares entitled to vote thereon.


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        Certificate of Amendment of the Certificate of Incorporation of

                              MEDO INDUSTRIES, INC.

                under Section 805 of the Business Corporation Law

IT IS HEREBY CERTIFIED THAT:

      (1)   The name of the corporation is MEDO INDUSTRIES, INC.

      (2)   The certificate of incorporation was filed by the department of
            state on the 20th day of September 1972.

      (3)   The certificate of incorporation of this corporation is hereby
            amended to effect the following change*

            To change the capitalization of the Corporation from 200 shares
      without par value of which 100 are issued and 100 are unissued into 200
      shares without par value of which 180 shall be Class A Voting Shares and
      20 shall be Class B Non-voting Shares. The currently authorized and issued
      100 shares without par value shall be changed into the newly authorized
      Class A Voting Shares at the rate of one for one. The currently authorized
      and unissued 100 shares shall be changed into 80 Class A Voting Shares and
      20 Class B Non-voting Shares at the rate of one for one. Paragraph
      "FOURTH" of the Certificate of Incorporation, which sets forth the
      capitalization, is amended to read as follows:

            "FOURTH: The aggregate number of shares which this Corporation shall
            have authority to issue is 200 shares, which are to be divided into
            two classes as follows:

            180 shares of no par value common stock (Class A) having full voting
            rights. The holders of such Class A stock shall be entitled to vote
            for the election of directors or in any corporate proceeding or upon
            any matter or question whatever pertaining to the Corporation.

            20 shares of no par value common stock (Class B). The holders of
            such Class B stock shall not be entitled to vote for the election of
            directors or in any corporate proceeding or upon any matter or
            question whatever pertaining to the Corporation unless otherwise
            required by law, but shall have all other rights and privleges
            enjoyed by holders of Class A stock."

            The Certificate of Incorporation is further amended to change the
      address for service of process. Paragraph "FIFTH", which sets forth the
      address for service of process, is amended to read as follows:

            "FIFTH: The Secretary of State is designated as agent of the
            Corporation upon whom process against it may be served. The Post
            Office address to which the Secretary of State shall mail a copy of
            any process against the Corporation served upon him is:

                        KLEIN, HEISLER & KLARREICH, P.C.
                       One Penn Plaza, New York, NY 10119


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      (4)   The amendment to the certificate of incorporation was authorized:

                  *     first, by vote of the board of directors.

                  *     and then at a meeting of shareholders by vote of a
                        majority of all the outstanding shares entitled to vote
                        thereon.


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