This excerpt taken from the SIRI 10-K filed Mar 1, 2007.
Payment. Each Restricted Stock Unit shall have a value equal to the Fair Market Value of a Share. Restricted Stock Units shall be paid in cash, Shares, other securities or other property, as determined in the sole discretion of the Committee, upon the lapse of the restrictions applicable thereto, or otherwise in accordance with the applicable Award Agreement. Dividends paid on any Shares of Restricted Stock may be paid directly to the Participant, withheld by the Company subject to vesting of the Restricted Shares pursuant to the terms of the applicable Award Agreement, or may be reinvested in additional Shares of Restricted Stock or in additional Restricted Stock Units, as determined by the Committee in its sole discretion.
Section 9. Performance Awards.