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                                                                    Exhibit 4.12

THE WARRANT REPRESENTED BY THIS CERTIFICATE AND ANY SECURITIES ACQUIRED UPON THE
EXERCISE OF THIS WARRANT HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
1933, AS AMENDED (THE "SECURITIES ACT"), OR ANY STATE SECURITIES LAWS AND
NEITHER THIS WARRANT NOR SUCH SECURITIES NOR ANY INTEREST THEREIN MAY BE
OFFERED, SOLD, TRANSFERRED, PLEDGED OR OTHERWISE DISPOSED OF EXCEPT (A) PURSUANT
TO AN EFFECTIVE REGISTRATION STATEMENT UNDER SUCH ACT OR SUCH LAWS OR (B) UPON
RECEIPT BY THE ISSUER OF AN OPINION OF COUNSEL, WHICH OPINION SHALL BE
REASONABLY SATISFACTORY TO ISSUER THAT SUCH TRANSFER IS EXEMPT FROM REGISTRATION
UNDER SUCH ACT AND SUCH LAWS.

                                   ----------

                        XM SATELLITE RADIO HOLDINGS INC.

                          COMMON STOCK PURCHASE WARRANT

                                   ----------

          This certifies that, for good and valuable consideration, XM Satellite
Radio Holdings Inc., a Delaware corporation (the "Company"), grants to General
Motors Corporation, a Delaware corporation ("GM"), the right to subscribe for
and purchase from the Company shares of the Company's Class A common stock, par
value $0.01 per share (the "Common Stock"), subject to the terms, conditions and
adjustments herein set forth.

          Certain capitalized terms used herein and not otherwise defined shall
have the meanings ascribed to them in Section 11.

Certificate No.  3

Name of Warrantholder:  General Motors Corporation

Number of Shares: 10,000,000

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1.   Number of Warrant Shares; Exercise Price.

     Subject to terms, conditions and adjustments as set forth in Section 7.1
and elsewhere herein, the Warrantholder shall have the right, in respect of this
Warrant, to purchase 10,000,000 shares of Common Stock (the "Warrant Shares") at
a purchase price per share of $3.18 (the "Exercise Price").

2.   Duration and Exercise Of Warrant; Limitations on Exercise; Payment of
     Taxes.

          2.1    Exercisability of Warrant. Subject to the terms and conditions
                 set forth herein, the right to exercise this Warrant shall vest
                 as of the Grant Date.

          2.2    Duration and Exercise of Warrant. Subject to the terms and
                 conditions set forth herein, the Warrant may be exercised, in
                 whole or in part, in respect of any Warrant Shares at any time
                 prior to the Expiration Date by the Warrantholder by:

                 (a)    the surrender of this Warrant to the Company, with a
                        duly executed Exercise Form specifying the number of
                        Warrant Shares to be purchased, during normal
                        business hours on any Business Day prior to the
                        Expiration Date; and

                 (b)    the delivery of payment to the Company, for the
                        account of the Company, by cash, by certified or bank
                        cashier's check or by wire transfer of immediately
                        available funds in accordance with wire instructions
                        that shall be provided by the Company upon request,
                        of the Exercise Price for the number of Warrant
                        Shares specified in the Exercise Form in lawful money
                        of the United States of America.

                 The Company agrees that such Warrant Shares shall be deemed to
                 be issued to the Warrantholder as the record holder of such
                 Warrant Shares as of the close of business on the date on which
                 this Warrant shall have been surrendered and payment made for
                 the Warrant Shares as aforesaid.

          2.3    Limitations on Exercise.

                 (a)    Notwithstanding anything to the contrary herein, the
                        number of shares of Common Stock that may be acquired by
                        the Warrantholder upon exercise shall be limited to the
                        extent necessary to ensure that, following such
                        exercise, the total number of shares of capital stock of
                        the Company then beneficially owned by the Warrantholder
                        and its Affiliates and any other Persons whose
                        beneficial ownership of Common Stock

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                        would be aggregated with the Warrantholder's for
                        purposes of Section 13(d) of the Exchange Act does not
                        exceed 19.9% of the total number of issued and
                        outstanding shares of Common Stock (including for such
                        purpose the shares of Common Stock issuable upon such
                        exercise). For such purposes, beneficial ownership shall
                        be determined in accordance with Section 13(d) of the
                        Exchange Act and the rules and regulations thereunder.
                        The Warrantholder acknowledges that the Company has not
                        reserved any shares of Common Stock for issuance upon
                        exercise of this Warrant, and therefore that this
                        Warrant may exercised only upon the obtaining by the
                        Company of the stockholder approval and amendment of its
                        Certificate of Incorporation under Section 4 hereof.

                 (b)    Notwithstanding anything to the contrary herein, this
                        Warrant may be exercised only upon (i) the delivery to
                        the Company of any certificates, legal opinions, and
                        other documents reasonably requested by the Company to
                        satisfy the Company that the proposed exercise of this
                        Warrant may be effected without registration under the
                        Securities Act, and (ii) receipt of approval of any
                        applicable Governmental Authority of the proposed
                        exercise, including, but not limited to, any approval
                        required pursuant to the Hart-Scott-Rodino Antitrust
                        Improvements Act of 1976, as amended, or from the FCC
                        (including if such exercise would result in any change
                        of control). The cost of such approvals, certificates,
                        legal opinions and other documents, if required, shall
                        be borne by the Warrantholder.

          2.4    Warrant Shares Certificate. A stock certificate or certificates
                 for the Warrant Shares specified in the Exercise Form shall be
                 delivered to the Warrantholder within five Business Days after
                 receipt of the Exercise Form and receipt of payment of the
                 purchase price. If this Warrant shall have been exercised only
                 in part, the Company shall, at the time of delivery of the
                 stock certificate or certificates, deliver to the Warrantholder
                 a new warrant evidencing the rights to purchase the remaining
                 Warrant Shares, which new warrant shall in all other respects
                 be identical with this Warrant.

          2.5    Payment of Taxes. The issuance of certificates for Warrant
                 Shares shall be made without charge to the Warrantholder for
                 any documentary, stamp or similar stock transfer or other
                 issuance tax in respect thereto; provided, however, that the
                 Warrantholder shall be required to pay any and all taxes which
                 may be payable in respect of any transfer involved in the
                 issuance and delivery of any certificate

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                 in a name other than that of the then Warrantholder as
                 reflected upon the books of the Company.

3.   Restrictions on Transfer; Restrictive Legends.

          3.1    Transfer of Warrant. This Warrant may not be transferred by
                 the Warrantholder, except with the written consent of the
                 Company; provided, however, that the Warrantholder may
                 transfer this Warrant to any Affiliate of the Warrantholder
                 without the prior written consent of the Company.

          3.2    Restrictive Legends.

                 (a)    Except as otherwise permitted by this Section, this
                        Warrant shall (and each Warrant issued in substitution
                        for any Warrant pursuant to Section 5 shall) be stamped
                        or otherwise imprinted with a legend in substantially
                        the following form:

                        THE WARRANT REPRESENTED BY THIS CERTIFICATE AND ANY
                        SECURITIES ACQUIRED UPON THE EXERCISE OF THIS WARRANT
                        HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
                        1933, AS AMENDED (THE "SECURITIES ACT"), OR ANY STATE
                        SECURITIES LAWS AND NEITHER THIS WARRANT NOR SUCH
                        SECURITIES NOR ANY INTEREST THEREIN MAY BE OFFERED,
                        SOLD, TRANSFERRED, PLEDGED OR OTHERWISE DISPOSED OF
                        EXCEPT (A) PURSUANT TO AN EFFECTIVE REGISTRATION
                        STATEMENT UNDER SUCH ACT OR SUCH LAWS OR (B) UPON
                        RECEIPT BY THE ISSUER OF AN OPINION OF COUNSEL, WHICH
                        OPINION SHALL BE REASONABLY SATISFACTORY TO THE ISSUER
                        THAT SUCH TRANSFER IS EXEMPT FROM REGISTRATION UNDER THE
                        SECURITIES ACT AND SUCH STATE SECURITIES LAWS.

                 (b)    Except as otherwise permitted by this Section, each
                        stock certificate for Warrant Shares issued upon the
                        exercise of any Warrant and each stock certificate
                        issued upon the direct or indirect transfer of any such
                        Warrant Shares shall be stamped or otherwise imprinted
                        with a legend in substantially the following form:

                        THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT
                        BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
                        AMENDED (THE "SECURITIES ACT"), OR ANY STATE SECURITIES
                        LAWS AND NEITHER THE

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                        SECURITIES NOR ANY INTEREST THEREIN MAY BE OFFERED,
                        SOLD, TRANSFERRED, PLEDGED OR OTHERWISE DISPOSED OF
                        EXCEPT (A) PURSUANT TO AN EFFECTIVE REGISTRATION
                        STATEMENT UNDER SUCH ACT OR SUCH LAWS OR (B) UPON
                        RECEIPT BY THE ISSUER OF AN OPINION OF COUNSEL, WHICH
                        OPINION SHALL BE REASONABLY SATISFACTORY TO THE ISSUER
                        THAT SUCH TRANSFER IS EXEMPT FROM REGISTRATION UNDER THE
                        SECURITIES ACT AND SUCH STATE SECURITIES LAWS.

                 (c)    Notwithstanding paragraphs (a) and (b) of this Section
                        3.2, the Warrantholder may require the Company to issue
                        to the Warrantholder a Warrant or a stock certificate
                        for Warrant Shares, in each case without a legend, if
                        either (i) the resale of such Warrant or such Warrant
                        Shares, as the case may be, has been registered under
                        the Securities Act or (ii) the Warrantholder has
                        delivered to the Company an opinion of legal counsel,
                        which opinion shall be addressed to the Company and be
                        reasonably satisfactory in form and substance to the
                        Company, to the effect that such registration is not
                        required with respect to the resale of such Warrant or
                        such Warrant Shares, as the case may be.

4.   Reservation and Registration of Shares, Etc.

     The Company covenants and agrees as follows:

                 (a)    all Warrant Shares which are issued upon the exercise
                        of this Warrant will, upon issuance, be validly
                        issued, fully paid, and nonassessable, not subject to
                        any preemptive rights, and free from all taxes,
                        liens, security interests, charges, and other
                        encumbrances with respect to the issue thereof;

                 (b)    at its next shareholders meeting, the Company will
                        seek shareholder approval to amend the Certificate of
                        Incorporation to increase the number of shares of
                        authorized Common Stock by a number sufficient for it
                        to reserve, and the Company covenants that it will,
                        immediately following receipt of such shareholder
                        approval, reserve and keep available out of its
                        authorized Common Stock, a sufficient number of
                        shares for the purposes of issuance upon exercise of
                        this Warrant; and

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                 (c)    the Company will, from time to time, take all such
                        action as may be required to assure that the par
                        value per share of the Warrant Shares is at all times
                        equal to or less than the then effective Exercise
                        Price.

5.   Loss or Destruction of Warrant.

     Subject to the terms and conditions hereof, upon receipt by the Company
of evidence reasonably satisfactory to it of the loss, theft, destruction or
mutilation of this Warrant and, in the case of loss, theft or destruction, of
such bond or indemnification as the Company may reasonably require, and, in the
case of such mutilation, upon surrender and cancellation of this Warrant, the
Company will execute and deliver a new Warrant of like tenor.

6.   Ownership of Warrant.

     The Company may deem and treat the Person in whose name this Warrant is
registered as the holder and owner hereof (notwithstanding any notations of
ownership or writing hereon made by anyone other than the Company) for all
purposes and shall not be affected by any notice to the contrary, until
presentation of this Warrant for registration of transfer in accordance with the
restrictions on transfer set forth herein.

7.   Certain Adjustments

          7.1    The number of Warrant Shares purchasable upon the exercise
                 of this Warrant and the Exercise Price shall be subject to
                 adjustment as follows:

                 (a)    Stock Dividends. If at any time after the date of the
                        issuance of this Warrant (i) the Company shall fix a
                        record date for the issuance of any stock dividend
                        payable in shares of Common Stock; or (ii) the number of
                        shares of Common Stock shall have been increased by a
                        subdivision or split-up of shares of Common Stock, then,
                        on the record date fixed for the determination of
                        holders of Common Stock entitled to receive such
                        dividend or immediately after the effective date of such
                        subdivision or split-up, as the case may be, the number
                        of shares to be delivered upon exercise of this Warrant
                        will be increased so that the Warrantholder will be
                        entitled to receive the number of shares of Common Stock
                        that the Warrantholder would have owned immediately
                        following such action had this Warrant been exercised
                        immediately prior thereto, and the Exercise Price will
                        be adjusted as provided below in paragraph (g).

                                        6

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                 (b)    Combination of Stock. If the number of shares of Common
                        Stock outstanding at any time after the date of the
                        issuance of this Warrant shall have been decreased by a
                        combination of the outstanding shares of Common Stock,
                        then, immediately after the effective date of such
                        combination, the number of shares of Common Stock to be
                        delivered upon exercise of this Warrant will be
                        decreased so that the Warrantholder thereafter will be
                        entitled to receive the number of shares of Common Stock
                        that the Warrantholder would have owned immediately
                        following such action had this Warrant been exercised
                        immediately prior thereto, and the Exercise Price will
                        be adjusted as provided below in paragraph (g).

                 (c)    Reorganization, etc. If any capital reorganization of
                        the Company, any reclassification of the Common Stock,
                        any consolidation of the Company with or merger of the
                        Company with or into any other Person, or any sale or
                        lease or other transfer of all or substantially all of
                        the assets of the Company to any other Person, shall be
                        effected in such a way that the holders of Common Stock
                        shall be entitled to receive stock, other securities or
                        assets (whether such stock, other securities or assets
                        are issued or distributed by the Company or another
                        Person) with respect to or in exchange for Common Stock,
                        then, upon exercise of this Warrant, the Warrantholder
                        shall have the right to receive the kind and amount of
                        stock, other securities or assets receivable upon such
                        reorganization, reclassification, consolidation, merger
                        or sale, lease or other transfer by a holder of the
                        number of shares of Common Stock that the Warrantholder
                        would have been entitled to receive upon exercise of
                        this Warrant had this Warrant been exercised immediately
                        before such reorganization, reclassification,
                        consolidation, merger or sale, lease or other transfer,
                        subject to adjustments that shall be as nearly
                        equivalent as may be practicable to the adjustments
                        provided for in this Section 7. If the Company effects
                        any such consolidation, merger or sale, lease or other
                        transfer, the Company shall ensure that prior to, or
                        simultaneously with, the consummation thereof, the
                        successor Person (if other than the Company) resulting
                        from such consolidation or merger, or such Person
                        purchasing, leasing or otherwise acquiring such assets,
                        shall assume, by written instrument, the obligation to
                        deliver to the Warrantholder the shares of stock,
                        securities or assets to which, in accordance with the
                        foregoing provisions, the Warrantholder may be entitled
                        and all other obligations of the Company under this
                        Warrant. The provisions of this paragraph (c) shall
                        apply to successive

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                        reorganizations, reclassifications, consolidations,
                        mergers, sales, leasing transactions and other
                        transfers.

                 (d)    Distributions to all holders of Common Stock. If the
                        Company shall, at any time after the date of issuance of
                        this Warrant, fix a record date to distribute to all
                        holders of its Common Stock any shares of capital stock
                        of the Company (other than Common Stock) or evidences of
                        its indebtedness or assets (not including regular cash
                        dividends and distributions paid from retained earnings
                        of the Company) or rights or warrants to subscribe for
                        or purchase any of its securities, then the
                        Warrantholder shall be entitled to receive, upon
                        exercise of this Warrant, that portion of such
                        distribution to which it would have been entitled had
                        the Warrantholder exercised its Warrant immediately
                        prior to the date of such distribution. At the time it
                        fixes the record date for such distribution, the Company
                        shall allocate sufficient reserves to ensure the timely
                        and full performance of the provisions of this
                        Subsection. The Company shall promptly (but in any case
                        no later than five Business Days prior to the record
                        date of such distribution) give notice to the
                        Warrantholder that such distribution will take place.

                 (e)    Fractional Shares. No fractional shares of Common
                        Stock or scrip shall be issued to the Warrantholder
                        in connection with the exercise of this Warrant.
                        Instead of any fractional shares of Common Stock that
                        would otherwise be issuable to the Warrantholder, the
                        Company will pay to the Warrantholder a cash
                        adjustment in respect of such fractional interest in
                        an amount equal to that fractional interest of the
                        then current Fair Market Value per share of Common
                        Stock.

                 (f)    Carryover. Notwithstanding any other provision of
                        this Section 7, no adjustment shall be made to the
                        number of shares of Common Stock to be delivered to
                        the Warrantholder (or to the Exercise Price) if such
                        adjustment represents less than 0.10% of the number
                        of shares to be so delivered, but any lesser
                        adjustment shall be carried forward and shall be made
                        at the time and together with the next subsequent
                        adjustment which together with any adjustments so
                        carried forward shall amount to 0.10% or more of the
                        number of shares to be so delivered.

                 (g)    Exercise Price Adjustment. Whenever the number of
                        Warrant Shares purchasable upon the exercise of this
                        Warrant is adjusted, as herein provided, the Exercise
                        Price payable upon the exercise of this Warrant shall
                        be adjusted by multiplying

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                        such Exercise Price immediately prior to such adjustment
                        by a fraction, of which the numerator shall be the
                        number of Warrant Shares purchasable upon the exercise
                        of the Warrant immediately prior to such adjustment, and
                        of which the denominator shall be the number of Warrant
                        Shares purchasable immediately thereafter.

          7.2    Rights Offering. In the event the Company shall effect an
                 offering of Common Stock pro rata among its stockholders,
                 the Warrantholder shall be entitled to elect to participate
                 in each and every such offering as if this Warrant had been
                 exercised immediately prior to each such offering. The
                 Company shall promptly (but in any case no later than five
                 Business Days prior to such rights offering) give notice to
                 the Warrantholder that such rights offering will take place.
                 The Company shall not be required to make any adjustment
                 with respect to the issuance of shares of Common Stock
                 pursuant to a rights offering in which the holder hereof
                 elects to participate under the provisions of this Section
                 7.2.

          7.3    Notice of Adjustments. Whenever the number of Warrant Shares
                 or the Exercise Price of such Warrant Shares is adjusted, as
                 herein provided, the Company at its expense shall promptly
                 give to the Warrantholder notice of such adjustment or
                 adjustments and a certificate of the independent public
                 accountants regularly employed by the Company or a firm of
                 independent public accountants of recognized national
                 standing selected by the Board of Directors of the Company
                 (which shall be appointed at the Company's expense) setting
                 forth the number of Warrant Shares and the Exercise Price of
                 such Warrant Shares after such adjustment, a brief statement
                 of the facts requiring such adjustment, and the computation
                 by which such adjustment was made.

          7.4    Notice of Extraordinary Corporate Events. In case the
                 Company after the date hereof shall propose to
                 (i) distribute any dividend (whether stock or cash or
                 otherwise) to the holders of shares of Common Stock or to make
                 any other distribution to the holders of shares of Common
                 Stock, (ii) offer to the holders of shares of Common Stock
                 rights to subscribe for or purchase any additional shares of
                 any class of stock or any other rights or options, or
                 (iii) effect any reclassification of the Common Stock (other
                 than a reclassification involving merely the subdivision or
                 combination of outstanding shares of Common Stock), any capital
                 reorganization, any consolidation or merger (other than a
                 merger in which no distribution of securities or other property
                 is to be made to holders of shares of Common Stock), any sale
                 or lease or transfer or other

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                 disposition of all or substantially all of its property, assets
                 and business, or the liquidation, dissolution or winding up of
                 the Company, then, in each such case, the Company shall give to
                 the Warrantholder notice of such proposed action, which notice
                 shall specify the date on which (a) the books of the Company
                 shall close, or (b) a record shall be taken for determining the
                 holders of Common Stock entitled to receive such stock
                 dividends or other distribution or such rights or options, or
                 (c) such reclassification, reorganization, consolidation,
                 merger, sale, transfer, other disposition, liquidation,
                 dissolution or winding up shall take place or commence, as the
                 case may be, and the date, if any, as of which it is expected
                 that holders of record of Common Stock shall be entitled to
                 receive securities or other property deliverable upon such
                 action. Such notice shall be given in the case of any action
                 covered by clause (i) or (ii) above at least ten days prior to
                 the record date for determining holders of Common Stock for
                 purposes of receiving such payment or offer, or in the case of
                 any action covered by clause (iii) above at least 30 days prior
                 to the date upon which such action takes place and 20 days
                 prior to any record date to determine holders of Common Stock
                 entitled to receive such securities or other property.

          7.5    Effect of Failure to Notify. Failure to file any certificate
                 or notice or to give any notice, or any defect in any
                 certificate or notice pursuant to Sections 7.3 and 7.4 shall
                 not affect the legality or validity of the adjustment to the
                 Exercise Price, the number of shares purchasable upon
                 exercise of this Warrant, or any transaction giving rise
                 thereto.

8.   Reports Under Securities Exchange Act of 1934. With a view to making
     available to the Warrantholder the benefits of Rule 144 promulgated under
     the Securities Act or any other similar rule or regulation of the SEC that
     may at any time permit the Warrantholder to sell securities of the Company
     to the public without registration ("Rule 144"), the Company agrees, at all
     times when the Warrantholder may need to rely on Rule 144 to sell such
     securities to the public without registration, to:

                 (a)    make and keep public information available, as those
                        terms are understood and defined in Rule 144, at all
                        times;

                 (b)    file with the SEC in a timely manner all reports and
                        other documents required of the Company under the
                        Securities Act and the Exchange Act; and

                 (c)    furnish to the Warrantholder so long as the
                        Warrantholder owns this Warrant, promptly upon request,
                        (i) a written statement by the Company that it has
                        complied with the reporting

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                        requirements of Rule 144 (at any time after 90 days
                        after the effective date of the first registration
                        statement filed by the Company), the Securities Act and
                        the Exchange Act (at any time after it has become
                        subject to such reporting requirements), (ii) a copy of
                        the most recent annual or quarterly report of the
                        Company and such other reports and documents so filed by
                        the Company, and (iii) such other information as may be
                        reasonably requested to permit the Warrantholder to sell
                        such securities without registration.

9.   Amendments. Any provision of this Warrant may be amended and the observance
     thereof may be waived (either generally or in a particular instance and
     either retroactively or prospectively), only with the written consent or
     approval of the Company and the Warrantholder. Any amendment or waiver
     effected in accordance with this Section shall be binding upon the
     Warrantholder and the Company.

10.  Expiration of the Warrant. The obligations of the Company pursuant to this
     Warrant shall terminate on the Expiration Date.

11.  Definitions.

      As used herein, unless the context otherwise requires, the following terms
have the following respective meanings:

      Affiliate: with respect to any Person, any other Person that directly, or
indirectly through one or more intermediaries, controls, is controlled by or is
under common control with, such specified Person, for so long as such Person
remains so associated to the specified Person.

      Business Day: any day other than a Saturday, Sunday or a day on which
banks are required or authorized by law to close in The City of New York, State
of New York.

      Bylaws: the bylaws of the Company, as the same may be amended and in
effect from time to time.

      Certificate of Incorporation: the Restated Certificate of Incorporation of
the Company, as the same may be amended and in effect from time to time.

      Common Stock: the meaning specified on the cover of this Warrant.

      Company: the meaning specified on the cover of this Warrant.

                                       11

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      Contractual Obligation: as to any Person, any agreement, undertaking,
contract, indenture, mortgage, deed of trust or other instrument to which such
Person is a party or by which it or any of its property is bound.

      Exchange Act: the Securities Exchange Act of 1934, as amended, or any
similar Federal statute, and the rules and regulations of the SEC thereunder,
all as the same shall be in effect at the time. Reference to a particular
section of the Exchange Act shall include a reference to a comparable section,
if any, of any such similar Federal statute.

      Exercise Form: a request to exercise this Warrant in respect of some or
all of the Warrant Shares in the form annexed hereto as Exhibit A.

      Exercise Price: the meaning specified in Section 1 of this Warrant.

      Expiration Date: Fifth anniversary of the Grant Date.

      Fair Market Value: With respect to a share of Common Stock as of a
particular date:

      (i)  if the Common Stock is registered under the Exchange Act, (a) the
           average of the daily closing sales prices of the Common Stock for the
           10 consecutive trading days immediately preceding such date, or
           (b) if the securities have been registered under the Exchange Act for
           less than 10 consecutive trading days before such date, then the
           average of the daily closing sales prices for all of trading days
           before such date for which closing sales prices are available, in the
           case of each of (a) and (b), as certified by any Vice President or
           the Chief Financial Officer of the Company; or

      (ii) If the Common Stock is not registered under the Exchange Act, then
           the Fair Market Value shall be as reasonably determined in good faith
           by the Board of Directors of the Company or a duly appointed
           committee thereof (which determination shall be reasonably described
           in the written notice given to the Warrantholder); provided, however,
           that if the Warrantholder reasonably objects to such determination of
           Fair Market Value by the Board of Directors or a duly appointed
           committee thereof, then such determination shall be referred to an
           unaffiliated investment banking firm of national reputation whose
           determination shall be final and binding upon the parties.

      For the purposes of clause (i) of this definition, the closing sales price
for each such trading day shall be: (1) in the case of a security listed or
admitted to trading on any United States national securities exchange or
quotation system, the closing sales price, regular way, on such day, or if no
sale takes place on such day, the average of the closing bid and asked prices on
such day; (2) in the case of a security

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<PAGE>

not then listed or admitted to trading on any national securities exchange or
quotation system, the last reported sale price on such day, or if no sale takes
place on such day, the average of the closing bid and asked prices on such day,
as reported by a reputable quotation source designated by the Company; (3) in
the case of a security not then listed or admitted to trading on any national
securities exchange or quotation system and as to which no such reported sale
price or bid and asked prices are available, the average of the reported high
bid and low asked prices on such day, as reported by a reputable quotation
service, or a newspaper of general circulation in the Borough of Manhattan, City
and State of New York, customarily published on each Business Day, designated by
the Company, or if there shall be no bid and asked prices on such day, the
average of the high bid and low asked prices, as so reported, on the most recent
day (not more than 30 days prior to the date in question) for which prices have
been so reported; and (4) if there are no bid and asked prices reported during
the 30 days prior to the date in question, the Fair Market Value shall be
determined as if the securities were not registered under the Exchange Act.

      FCC: the Federal Communications Commission.

      Governmental Authority: the government of any nation, state, city,
locality or other political subdivision of any thereof, and any entity
exercising executive, legislative, judicial, regulatory or administrative
functions of or pertaining to government or any international regulatory body
having or asserting jurisdiction over a Person, its business or its properties.

      Grant Date: _______, 200_.

      Lien: any mortgage, deed of trust, pledge, hypothecation, assignment,
encumbrance, lien (statutory or other), restriction or other security interest
of any kind or nature whatsoever.

      Person: any individual, firm, corporation, partnership, limited liability
company, trust, incorporated or unincorporated association, joint venture, joint
stock company, Governmental Authority or other entity of any kind.

     Requirement of Law: as to any Person, any law, treaty, rule, regulation,
qualification, license or franchise or determination of an arbitrator or a court
or other Governmental Authority, in each case applicable or binding upon such
Person or any of its property or to which such Person or any of its property is
subject or pertaining to any or all of the transactions contemplated hereby.

      Rule 144: the meaning specified in Section 8 of this Warrant.

      SEC: the Securities and Exchange Commission or any other Federal agency at
the time administering the Securities Act or the Exchange Act, whichever is the
relevant statute for the particular purpose.

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      Securities Act: the meaning specified on the cover of this Warrant, or any
similar Federal statute, and the rules and regulations of the SEC thereunder,
all as the same shall be in effect at the time. Reference to a particular
section of the Securities Act, shall include a reference to the comparable
section, if any, of any such similar Federal statute.

      Warrant Shares: the meaning specified on the cover of this Warrant.

      Warrantholder: GM (for so long as GM holds any interest in the Warrant)
and any transferee of GM's rights in the Warrant that are transferred in
accordance with Section 3.1 hereof (for so long as such transferee holds such
rights).

12.  No Impairment. The Company shall not by any action, including, without
     limitation, amending its Certificate of Incorporation or through any
     reorganization, transfer of assets, consolidation, merger, dissolution,
     issue or sale of securities or any other voluntary action, avoid or seek to
     avoid the observance or performance of any of the terms of this Warrant,
     but will at all time in good faith assist in the carrying out of all such
     terms and in the taking of all such reasonable actions as may be necessary
     or appropriate to protect the rights of the Warrantholder against
     impairment. Without limiting the generality of the foregoing, the Company
     shall (a) take all such actions as may be necessary or appropriate in order
     that the Company may validly and legally issue fully paid and nonassesable
     shares of Common Stock upon the exercise of this Warrant, and (b) provide
     reasonable assistance to the Warrantholder in obtaining all authorizations,
     exemptions or consents from any Governmental Authority which may be
     necessary in connection with the exercise of this Warrant.

13.  Miscellaneous.

          13.1   Entire Agreement. This Warrant constitutes the entire agreement
                 between the Company and the Warrantholder with respect to the
                 Warrant.

          13.2   Binding Effects; Benefits. This Warrant shall inure to the
                 benefit of and shall be binding upon the Company and the
                 Warrantholder and their respective heirs, legal
                 representatives, permitted successors and permitted assigns.
                 Nothing in this Warrant, expressed or implied, is intended
                 to or shall confer on any Person other than the Company and
                 the Warrantholder, or their respective heirs, legal
                 representatives, permitted successors or permitted assigns,
                 any rights, remedies, obligations or liabilities under or by
                 reason of this Warrant.

          13.3   Section and Other Headings. The section and other headings
                 contained in this Warrant are for reference purposes only
                 and shall

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<PAGE>

                 not be deemed to be a part of this Warrant or to affect the
                 meaning or interpretation of this Warrant.

          13.4   Pronouns. All pronouns and any variations thereof refer to
                 the masculine, feminine or neuter, singular or plural, as
                 the context may require.

          13.5   Further Assurances. Each of the Company and the
                 Warrantholder shall do and perform all such further acts and
                 things and execute and deliver all such other certificates,
                 instruments and documents as the Company or the
                 Warrantholder may, at any time and from time to time,
                 reasonably request in connection with the performance of any
                 of the provisions of this Warrant.

          13.6   Notices. All notices and other communications required or
                 permitted to be given under this Warrant shall be in writing
                 and shall be deemed to have been duly given if (i) delivered
                 personally or (ii) sent by facsimile or recognized overnight
                 courier or by United States first class certified mail,
                 postage prepaid, to the parties hereto at the following
                 addresses or to such other address as any party hereto shall
                 hereafter specify by notice to the other party hereto:

                 if to the Company, addressed to:

                 XM Satellite Radio Holdings Inc.
                 1500 Eckington Place, N.E.
                 Washington, D.C. 20002
                 Attention: Chief Financial Officer

                 if to the Warrantholder, addressed to:

                 General Motors Corporation
                 100 Renaissance Center
                 Detroit, MI 48265
                 Attention:  General Counsel

                 Except as otherwise provided herein, all such notices and
                 communications shall be deemed to have been received (a) on
                 the date of delivery thereof, if delivered personally or
                 sent by facsimile, (b) on the second Business Day following
                 delivery into the custody of an overnight courier service,
                 if sent by overnight courier, provided that such delivery is
                 made before such courier's deadline for next-day delivery,
                 or (c) on the third Business Day after the mailing thereof.

          13.7   Separability. Any term or provision of this Warrant which is
                 invalid or unenforceable in any jurisdiction shall, as to
                 such jurisdiction, be

                                       15

<PAGE>

                 ineffective to the extent of such invalidity or
                 unenforceability without rendering invalid or unenforceable the
                 terms and provisions of this Warrant or affecting the validity
                 or enforceability of any of the terms or provisions of this
                 Warrant in any other jurisdiction.

          13.8   Governing Law. This Warrant shall be deemed to be a contract
                 made under the laws of New York and for all purposes shall
                 be governed by and construed in accordance with the laws of
                 such State applicable to such agreements made and to be
                 performed entirely within such State, except that all
                 matters relating to issuances of stock shall be governed by
                 Delaware General Corporation Law.

          13.9   No Rights or Liabilities as Stockholder. Nothing contained
                 in this Warrant shall be deemed to confer upon the
                 Warrantholder any rights as a stockholder of the Company or
                 as imposing any liabilities on the Warrantholder to purchase
                 any securities whether such liabilities are asserted by the
                 Company or by creditors or stockholders of the Company or
                 otherwise.

          13.10  Representations of the Company. The Company hereby represents
                 and warrants, as of the date hereof, to the Warrantholder as
                 follows:

                 (a)    Corporate Existence and Power. The Company (i) is a
                        corporation duly incorporated, validly existing and in
                        good standing under the laws of the State of Delaware;
                        (ii) has all requisite corporate power and authority to
                        own and operate its property, to lease the property it
                        operates as lessee and to conduct the business in which
                        it is engaged; and (iii) has the corporate power and
                        authority to execute, deliver and perform its
                        obligations under this Warrant. The Company is duly
                        qualified to do business as a foreign corporation in,
                        and is in good standing under the laws of, each
                        jurisdiction in which the conduct of its business or the
                        nature of the property owned requires such
                        qualification, except where the failure to qualify would
                        not, individually or in the aggregate, result in a
                        material adverse effect on the business, operations,
                        affairs, assets, liabilities, financial condition or
                        properties of the Company and its subsidiaries, taken as
                        a whole.

                 (b)    Corporate Authorization; No Contravention. Subject to
                        receipt of the approval of the Company's stockholders of
                        the proposed amendment to the Company's certificate of
                        incorporation, as discussed in Section 4(b) hereof, and
                        the subsequent reservation for issuance of the Warrant
                        Shares, the execution, delivery and performance by the
                        Company of this Warrant and the

                                       16

<PAGE>

                        transactions contemplated hereby, including, without
                        limitation, the sale, issuance and delivery of the
                        Warrant Shares, (i) have been duly authorized by all
                        necessary corporate action of the Company; (ii) do not
                        contravene the terms of the Certificate of Incorporation
                        or Bylaws; and (iii) do not violate, conflict with or
                        result in any breach or contravention of, or the
                        creation of any Lien under, any Contractual Obligation
                        of the Company or any Requirement of Law applicable to
                        the Company. No event has occurred and no condition
                        exists which, upon notice or the passage of time (or
                        both), would constitute a default under any indenture,
                        mortgage, deed of trust, credit agreement, note or other
                        evidence of indebtedness or other material agreement of
                        the Company or the Certificate of Incorporation or
                        Bylaws.

                 (c)    Issuance of Warrant Shares. Subject to receipt of the
                        approval of the Company's stockholders of the proposed
                        amendment to the Company's certificate of incorporation,
                        as discussed in Section 4(b) hereof, and the subsequent
                        reservation for issuance of the Warrant Shares, the
                        Warrant Shares will be duly authorized and reserved for
                        issuance. When issued, such shares will be validly
                        issued, fully paid and non-assessable, and free and
                        clear of all Liens and preemptive rights, and the
                        holders thereof shall be entitled to all rights and
                        preferences accorded to a holder of Common Stock.

                 (d)    Binding Effect. This Warrant has been duly executed and
                        delivered by the Company and constitutes the legal,
                        valid and binding obligation of the Company enforceable
                        against the Company in accordance with its terms, except
                        as enforceability may be limited by applicable
                        bankruptcy, insolvency, fraudulent conveyance or
                        transfer, moratorium or other similar laws affecting the
                        enforcement of creditors' rights generally and by
                        general principles of equity.

                                       17

<PAGE>

     IN WITNESS WHEREOF, the Company has caused this Warrant to be signed by
its duly authorized officer.

                                       XM SATELLITE RADIO HOLDINGS INC.

                                       By: Hugh Panero


                                            /s/ Hugh Panero
                                           -------------------------------------
                                           Hugh Panero
                                           President and Chief Executive Officer

Dated:  January 28, 2003


Attest:

By:  Joseph M. Titlebaum


       /s/ Joseph M. Titlebaum
     -----------------------------
     Joseph M. Titlebaum
     Senior Vice President, General Counsel
       and Secretary

                                       18

<PAGE>

                                    Exhibit A

                                  EXERCISE FORM

                 (To be executed upon exercise of this Warrant)

     The undersigned hereby irrevocably elects to exercise the right,
represented by this Warrant, to purchase __________ shares of Common Stock and
herewith tenders payment for such Common Stock to the order of XM Satellite
Radio Holdings Inc. in the amount of $__________, which amount includes payment
of the par value for the Common Stock, in accordance with the terms of this
Warrant. The undersigned requests that a certificate for such shares of Common
Stock be registered in the name of __________________ and that such certificates
be delivered to __________________ whose address is
___________________________________.

Dated:
      --------------

                                       Signature
                                                 ------------------------------

                                                 ------------------------------
                                                 (Print Name)

                                                 ------------------------------
                                                 (Street Address)

                                                 ------------------------------
                                                 (City)  (State)  (Zip Code)

Signed in the Presence of:

----------------------------


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