California Code, Revenue and Taxation Code - RTC § 6902.1

(a) Upon receipt of proof to its satisfaction that, in connection with the sale, through a dealer and not on the dealer's own account, of a used mobilehome on which the registration was transferred during the period from January 1, 1977 to January 1, 1980, and on which use tax has been paid on items not part of a mobilehome as a vehicle as set forth in Sections 6012.2 and 6276.1, the State Board of Equalization shall refund such overpayment to the purchaser of the mobilehome.

(b) Notwithstanding the provisions of Section 6902, any purchaser entitled to a refund pursuant to subdivision (a) may file a claim for refund until December 31, 1982.