California Code, Vehicle Code - VEH § 22952

(a) Tows or removes or authorizes the towing and removal of any vehicle within 24 hours of the expiration of the period for which a particular fee is charged.  This subdivision shall not affect or limit any parking lot operator from charging parking fees in accordance with his posted schedule for the additional time such vehicle is parked.

(b) Tows or removes or authorizes the towing and removal of any vehicle when such parking facilities are held open for public use and there was no attendant on duty or other facilities permitting the patron to pay or remit the parking charges at the time such vehicle was first parked.  This subdivision shall not affect or limit any parking lot operator from charging parking fees in accordance with his posted schedule for the time such vehicle is parked.