All duties, powers and authority relating to the enforcement of the motor tax laws for Mississippi shall be vested solely in the State Tax Commission, except that the administration and enforcement of such laws as are applicable to the collection of license taxes due on private commercial carriers of property and private carriers of property of a gross weight of ten thousand (10,000) pounds and less, and on private passenger vehicles, school buses, taxicabs, ambulances and hearses, shall be jointly administered by the Tax Commission and the tax collectors of the several counties. If any sheriff, constable or municipal law enforcement officer shall enforce the collection of any delinquent motor vehicle privilege license tax, together with the penalty thereon provided by law, then such sheriff, constable or municipal law enforcement officer shall be entitled to one-half (½) of said delinquency and penalty, but he shall not be entitled to such one-half (½) of such delinquency and penalty unless he actually and directly enforced the collection thereof. Provided, however, the one-half (½) of the delinquency and penalty due the sheriff or municipal law enforcement officer shall be paid into a special fund of the county or municipality, as the case may be, and may be appropriated and expended by the governing authorities of the county or municipality for any lawful purpose. No persons other than those named in this article shall ever be entitled to receive any portion of a delinquency or penalty on motor vehicle privilege license taxes for the collection of same. All delinquent privilege taxes and penalties imposed and collected under the provisions of this article shall be handled and disposed of in the same manner as the regular taxes.