California Code, Vehicle Code - VEH § 40520

(b)(1) If a notice to appear is sent to a car rental or leasing company, as the registered owner of the vehicle, the company may return the notice of nonliability pursuant to paragraph (2), if the violation occurred when the vehicle was either leased or rented and operated by a person other than an employee of the rental or leasing company.

(2) If the affidavit of nonliability is returned to the issuing agency by the registered owner within 30 days of the mailing of the notice to appear together with the proof of a written rental agreement or lease between a bona fide renting or leasing company and its customer and that agreement identifies the renter or lessee and provides the driver's license number, name, and address of the renter or lessee, the agency shall cancel the notice for the registered owner to appear and shall, instead, issue a notice to appear to the renter or lessee identified in the affidavit of nonliability.