(a)). (B) Refundable credit may be transferred (i) In general A taxpayer may, in connection with the purchase of a new qualified fuel-efficient motor vehicle, transfer any refundable credit described in subparagraph (A) to any person who is in the trade or business of selling new qualified fuel-efficient motor vehicles and who sold such vehicle to the taxpayer, but only if such person clearly discloses to such taxpayer, through the use of a window sticker attached to the new qualified fuel-efficient vehicle— (I) the amount of the refundable credit described in subparagraph (A) with respect to such vehicle, and (II) a notification that the taxpayer will not be eligible for any credit under section 30D with respect to such vehicle unless the taxpayer elects not to have this section apply with respect to such vehicle. (ii) Certification A transferee of a refundable credit described in subparagraph (A) may not claim such credit unless such claim is accompanied by a certification to the Secretary that the transferee reduced the price the taxpayer paid for the new qualified fuel-efficient motor vehicle by the entire amount of such refundable credit. (iii) Consent required for revocation Any transfer under clause (i) may be revoked only with the consent of the Secretary. (iv) Regulations The Secretary may prescribe such regulations as necessary to ensure that any refundable credit described in clause (i) is claimed once and not retransferred by a transferee. (d) Other definitions For purposes of this section— (1) Fuel-economy rating The term fuel-economy rating means, with respect to any motor vehicle, the combined fuel-economy rating for such motor vehicle, expressed in gallons per mile, determined in accordance with section 32904 of title 49, United States Code. (2) Model year The term model year has the meaning given such term under section 32901(a) of such title 49. (3) Motor vehicle The term motor vehicle means any vehicle which is manufactured primarily for use on public streets, roads, and highways (not