Minn. Stat. § 297A.90
Subd. 1. Registration; records.
(b) As used in this section, "person" means:
(3) one who transports tangible personal property in interstate commerce, pursuant to contracts with persons described in clause (1) or (2).
Persons qualifying under clause (2) or (3) must maintain on a current basis the same type of mileage records that are required by persons specified in clause (1) by the United States Department of Transportation.
Subd. 2. Payment of tax.
(c) The total cost of such equipment and parts and accessories attached or to be attached to such equipment must be multiplied by a fraction. The numerator of the fraction is the Minnesota mileage as reported on the current pro rata application provided for in section 168.187 and the denominator of the fraction is the total mileage reported on the current pro rata registration application. The amount so determined must be multiplied by the tax rate to obtain the tax due.
In computing the tax under this section "sales price" does not include the amount of any taxes imposed directly on the consumer that are separately stated on the invoice, bill of sale, or similar document given to the purchaser.
Subd. 3. Registration subsequent to payment of tax.
A person who has paid the tax under this chapter or chapter 297B and who meets the requirements of this section at the time of the sale, but was not registered under this section at the time of the sale, may register as a retailer, make a return, and file for a refund of the difference between the tax calculated under this chapter or chapter 297B and the tax calculated under subdivision 2.
Subd. 4. Agreement with commissioner of public safety.
Notwithstanding subdivisions 1 to 3, the commissioner may enter into an agreement with the commissioner of public safety whereby, upon approval of both commissioners, the commissioner of public safety shall collect the sales tax on motor vehicles from persons defined in subdivision 1. For the purpose of collecting the tax, the commissioner of public safety shall act as the agent of the commissioner of revenue and shall be subject to all rules consistent with this chapter that may be prescribed by the commissioner.