(a) Except as provided by Subsection (c), the tax authorized by this subchapter is imposed at a rate in increments of one-eighth of one percent, not to exceed five percent, on the gross rental receipts from the rental in the municipality or county of a motor vehicle.
(b) The ballot proposition at the election held to adopt the tax must specify the maximum rate of the tax to be adopted.
(c) A county with a population of more than 2.5 million that is adjacent to a county with a population of more than 2.1 million may impose the tax authorized by this subchapter at a rate not to exceed six percent on the gross rental receipts from the rental in the county of a motor vehicle.