California Code, Vehicle Code - VEH § 12001

(a) Any person who sells and installs new parts in passenger cars, in the ordinary course of his business, shall provide the customer with an invoice which identifies by brand name, or other comparable designation, the part or parts installed.

(b) Any person who sells and installs used or factory rebuilt parts in passenger cars, in the ordinary course of his business, shall provide the customer with an invoice which specifically designates the used part or parts installed.

(c) This section shall not apply to any fitting or other device necessary to the installation of any new, used or factory rebuilt part subject to the provisions of this section.