California Code, Vehicle Code - VEH § 1655

(a) The director and deputy director of the department, the Deputy Director, Investigations Division, the Chief, Field Investigations Branch, and the investigators of the department, including rank-and-file, supervisory, and management personnel, shall have the powers of peace officers for the purpose of enforcing those provisions of law committed to the administration of the department or enforcing the law on premises occupied by the department.

(b) Any person designated in subdivision (a) may inspect any vehicle of a type required to be registered under this code, or any component part thereof, in any garage, repair shop, parking lot, used car lot, automobile dismantler's lot, steel mill, scrap metal processing facility, or other establishment engaged in the business of selling, repairing, or dismantling vehicles, or reducing vehicles or the integral parts thereof to their component materials for the purpose of investigating the title and registration of the vehicle, inspecting wrecked or dismantled vehicles, or locating stolen vehicles.