Nothing in this Act or the amendments made by this Act shall be construed to create any inference with respect to the proper tax treatment of any subsidy received directly or indirectly from a public utility, a storm water management provider, or a State or local government for any water conservation measure or storm water management measure before January 1, 2021. IV Greening the Fleet and Alternative Vehicles 401. Modification of limitations on new qualified plug-in electric drive motor vehicle credit (a) In general Section 30D(e) is amended to read as follows: (e) Limitation on number of new qualified plug-In electric drive motor vehicles eligible for credit (1) In general In the case of any new qualified plug-in electric drive motor vehicle sold after the date of the enactment of the GREEN Act of 2020 — (A) if such vehicle is sold during the transition period, the amount determined under subsection (b)(2) shall be reduced by $500, and (B) if such vehicle is sold during the phaseout period, only the applicable percentage of the credit otherwise allowable under subsection (a) shall be allowed. (2) Transition period For purposes of this subsection, the transition period is the period subsequent to the first date on which the number of new qualified plug-in electric drive motor vehicles manufactured by the manufacturer of the vehicle referred to in paragraph (1) sold for use in the United States after December 31, 2009, is at least 200,000. (3) Phaseout period (A) In general For purposes of this subsection, the phaseout period is the period beginning with the second calendar quarter following the calendar quarter which includes the first date on which the number of new qualified plug-in electric drive motor vehicles manufactured by the manufacturer of the vehicle referred to in paragraph (1) sold for use in the United States after December 31, 2009, is at least 600,000. (B) Applicable percentage For purposes of paragraph (1)(B), the applicable percentage is— (i) 50 percent for the first calendar quarter of the