(a) The taxes imposed by this chapter do not apply to the retail sale of a motor vehicle that is transported out of state, prior to any use in this state other than the transportation of the vehicle out of state, for use exclusively outside this state.
(b) To qualify for the exemption provided by this section the purchaser of a motor vehicle must sign at the time of the purchase an exemption certificate that:
(1) is on a form designated by the comptroller;
(2) contains all information the comptroller considers reasonable;
(3) is signed by the purchaser; and
(4) provides that the purchaser, by signing the certificate, authorizes the comptroller to provide a copy of the certificate to the state of intended use and registration.