California Code, Vehicle Code - VEH § 5301

(a) Notwithstanding any other provision of this code and Part 5 (commencing with Section 10701) of Division 2 of the Revenue and Taxation Code, the registered owner or lessee of a fleet of vehicles consisting of commercial motor vehicles base plated in the state, or passenger automobiles may, upon payment of appropriate fees, apply to the department for license plates, permanent decals, and registration cards.

(c) With the concurrence of both the department and the participant, the changes made in this section by the enactment of the Commercial Vehicle Registration Act of 2001 shall not affect those participants who were lawfully participating in the permanent fleet registration program on December 31, 2001.  Any fleet that qualifies for permanent fleet registration as of December 31, 2001, will continue to count trailers to qualify as a fleet until January 1, 2007.  However, five years following the implementation of the permanent trailer identification program, all participants in the permanent fleet registration program shall meet the requirements of this section in order to continue enrollment in the program described in this section.