(C) for a vehicle purchased during the third calendar year following such determination year, 25 percent, and (D) for a vehicle purchased during any calendar year subsequent to the year described in subparagraph (C), 0 percent. . (3) Effective date The amendments made by this subsection shall apply to property purchased after December 31, 2017. (b) Alternative fuel vehicle refueling property credit (1) In general Paragraph (1) of section 30C(g) is amended by striking December 31, 2017 and inserting December 31, 2020 . (2) Effective date The amendments made by this subsection shall apply to property placed in service after December 31, 2017. (c) New qualified plug-In electric drive motor vehicles (1) 2- and 3-wheeled plug-in electric vehicles (A) In general Clause (ii) of section 30D(g)(3)(E) is amended by striking in the case of a vehicle that has 2 wheels, after December 31, 2014, and before January 1, 2018 and inserting after December 31, 2014 . (B) Effective date The amendments made by this paragraph shall apply to vehicles acquired after December 31, 2017. (2) Elimination on limitation on number of vehicles eligible for credit (A) In general Section 30D , as amended by paragraph (1), is amended— (i) by striking subsection (e), and (ii) by redesignating subsections (f) and (g) as subsections (e) and (f), respectively. (B) Conforming amendment Paragraph (37) of section 1016(a) is amended by striking section 30D(f)(1) and inserting section 30D(e)(1) . (C) Effective date The amendments made by this paragraph shall apply to vehicles sold after the date of the enactment of this Act. (3) Phaseout Section 30D , as amended by paragraph (2), is amended by adding at the end the following: (g) Credit phase-Out for new qualified plug-In electric drive motor vehicles (1) In general Following a determination by the Secretary under section 45U(d)(1) that the greenhouse gas emissions from transportation fuel produced and sold at retail annually in the United States are equal to or less than 50 percent of the greenhouse gas