CA Veh Code Section 4601.5

Notwithstanding Section 4601, the registration for vehicles registered pursuant to the Partial Year Registration Program as described in Article 5 (commencing with Section 9700) of Chapter 6 of Division 3, expires at midnight of December 31 of the registration year. However, for the purposes of applying any future reductions or increases in the vehicle license fee, the vehicle registrations subject to this section shall be deemed to have a final expiration date in the succeeding calendar year.