Cal. Veh. Code § 11711.3

A person acting as a dealer, who was not licensed as a dealer as required by this article, or a person acting as a lessor-retailer, who was not licensed as a lessor-retailer as required by Chapter 3.5 (commencing with Section 11600), may not enforce any security interest or bring or maintain any action in law or equity to recover any money or property or obtain other relief from the purchaser or lessee of a vehicle in connection with a transaction in which the person was, at the time of the transaction, required to be licensed as a dealer or a lessor-retailer.