the aggregate amount of income that would have been required to be recognized in the liquidation year had the taxpayer elected to apply the provisions of section 473 of the Internal Revenue Code of 1986 and not made the election in paragraph (1), plus (B) interest thereon at the underpayment rate established under section 6621 of such Code. (3) Elections (A) In general Except to the extent provided in subparagraph (B), an election under paragraph (1) with respect to any specified taxable year shall be made by the due date (including extensions) for filing the taxpayer’s return of tax for such taxable year and in such manner as the Secretary may prescribe. Once made, any such election shall be irrevocable. (B) Certain elections treated as change in method of accounting In the case of an election with respect to a specified taxable year for which the return of tax has already been filed before the date of the enactment of this Act, any election under paragraph (1) for such specified taxable year may be made on the return of tax for the first taxable year ending after the date of the enactment of this Act and shall be treated for purposes of section 481 of the Internal Revenue Code of 1986 as a change in method of accounting initiated by the taxpayer and made with the consent of the Secretary. (c) Definitions For purposes of this section— (1) Specified taxable year The term specified taxable year means any liquidation year ending after March 12, 2020, and before January 1, 2022. (2) New motor vehicle The term new motor vehicle means a motor vehicle— (A) which is described in section 163(j)(9)(C)(i) of the Internal Revenue Code of 1986, and (B) the original use of which has not commenced. (3) Secretary The term Secretary means the Secretary of the Treasury or the Secretary’s delegate. (4) Other terms Except as otherwise provided in this section, terms used in this section which are also used in section 473 of the Internal Revenue Code of 1986 shall have the same meaning as when used in such section 473.