(1) Whenever a motor vehicle of any description is converted to a motor vehicle of other description referred to in Schedule I, the motor vehicle as so converted shall be subject to additional tax as leviable under this Act with effect from the date on which such conversion takes place.
(2) Whenever a motor vehicle ceases to be a motor vehicle of any description referred to in Schedule I, such portion of the additional tax shall be refundable on claim within fifteen days of such conversion as may seem to the taxing authority to be refundable, calculation being made on the basis of the period for which the vehicle bore the description of the motor vehicle referred to in Schedule Ito come within the purview of additional tax under this Act.
(3) No additional tax under this Act shall be payable in respect of a motor vehicle for the period for which such additional tax has already been paid by any person.