Notwithstanding any other provision of law, the Commissioner may from time to time adopt rules to provide that "taxable cost" shall not reflect a diminution for trade-in arising from a purchase of a motor vehicle in a state that does not allow a deduction for trade-in in the computation of the "taxable cost" or similar tax base in the computation of taxes imposed by a motor vehicle sales and use tax in that state.
32 V.S.A. § 8908