(b) Except to the extent that the transfer of a shared vehicle
described in subdivision (a) of this section, or section eleven hundred
ninety-three of this article, has already been or will be subject to the
tax imposed under such subdivision or section and except as otherwise
exempted under this article, there is hereby imposed on every shared
vehicle driver and there shall be paid a use tax for the use within the
metropolitan commuter transportation district as established by section
twelve hundred sixty-two of the public authorities law of any shared
vehicle by the shared vehicle driver. For purposes of this subdivision,
the tax shall be at the rate of three percent of the gross receipts paid
or contracted to be paid for such shared vehicle.