Notwithstanding any other provision of law to the contrary, for tax year 1998, and for each tax year thereafter, the amount of personal property tax imposed upon motor vehicles having a gross vehicle weight of more than 12,000 pounds but less than 20,001 pounds, shall be computed in accordance with the provisions of Kan. Stat. Ann. § 79-5101 et seq., and amendments thereto, but shall be required to be paid at the time required by Kan. Stat. Ann. § 79-2004a, and amendments thereto, and the provisions of such section shall be applicable to the collection thereof.