California Code, Business and Professions Code - BPC § 9844.5

No lien or other right to maintain possession of the equipment pending payment of charges for repair or installation, including those arising from Chapter 6 (commencing with Section 3046) of Title 14, Part 4, Division 3 of the Civil Code, shall exist where the total charges levied for the repair or installation of such equipment exceeds the higher of (1) any amount estimated in writing pursuant to Section 9844, or (2) a written revision of such estimate signed and dated by the owner of the equipment, or in lieu thereof an oral revision of the written estimate, authorized by the owner and fully documented by the service dealer.