Cal. Veh. Code § 5004
(a) Notwithstanding any other provision of this code, any owner of a vehicle described in paragraph (1), (2), or (3) which is operated or moved over the highway primarily for the purpose of historical exhibition or other similar purpose shall, upon application in the manner and at the time prescribed by the department, be issued special identification plates for the vehicle:
(b) The special identification plates assigned to motor vehicles with an engine of 16 or more cylinders manufactured prior to 1965 and to any motor vehicle manufactured in the year 1922 and prior thereto shall run in a separate numerical series, commencing with “Horseless Carriage No. 1”.
The special identification plates assigned to vehicles specified in paragraph (3) of subdivision (a) shall run in a separate numerical series, commencing with “Historical Vehicle No. 1”.
Each series of plates shall have different and distinguishing colors.