California Vehicle Code
Only a dealer, a person described in Section 286, or the registered owner of record shall sell or offer for sale a vehicle of a type required to be registered pursuant to Division 3 (commencing with Section 4000) or identified pursuant to Division 16.5 (commencing with Section 38000), except as provided in Section 12121.
(a) Section 12120 does not apply to a dealer licensed pursuant to Chapter 4 (commencing with Section 11700) when acting under authority of the license, or to his or her authorized agent.
(b) Section 12120 does not prohibit the sale of a vehicle by any of the following persons not engaged in the business of selling vehicles:
(1) Anyone related by blood, adoption, or marriage to the registered owner.
(2) The receiver, administrator, executor, guardian, or other person appointed by, or acting under, a judgment or order of any court.
(3) The trustee of a trust in which the vehicle is registered as an asset.
(4) Any public officer in the performance of his or her official duties.
(5) An attorney on behalf of a client who is the registered owner.
(6) The owner, officer, or designated representative of a business in whose name the vehicle is registered.
(7) The legal owner as shown on the certificate of ownership.
(8) A person who has prior written authorization from the registered owner of the vehicle, and that person does not receive or expect to receive a commission, money, brokerage fees, profit, or any other thing of value from either the seller or purchaser of the vehicle.
(9) An insurer selling the salvage of one of its insured's vehicle or the stolen vehicle of one of its insured which has been recovered.