California Code, Vehicle Code - VEH § 1671

(a) The established place of business of a dealer, remanufacturer, remanufacturer branch, manufacturer, manufacturer branch, distributor, distributor branch, automobile driving school, or traffic violator school shall have an office and a dealer, manufacturer, or remanufacturer shall also have a display or manufacturing area situated on the same property where the business peculiar to the type of license issued by the department is or may be transacted. When a room or rooms in a hotel, roominghouse, apartment house building, or a part of any single- or multiple-unit dwelling house is used as an office or offices of an established place of business, the room or rooms shall be devoted exclusively to and occupied for the office or offices of the dealer, manufacturer, manufacturer branch, remanufacturer, remanufacturer branch, distributor, distributor branch, automobile driving school, or traffic violator school, shall be located on the ground floor, and shall be so constructed as to provide a direct entrance into the room or rooms from the exterior of the building. A dealer who does not offer new or used vehicles for sale at retail, a dealer who has been issued an autobroker's endorsement to his or her dealer's license and who does not also sell motor vehicles at retail, or a dealer who is a wholesaler involved for profit only in the sale of vehicles between licensed dealers, shall have an office, but a display area is not required.

(b) The established place of business of an automobile dismantler shall have an office and a dismantling area located in a zone properly zoned for that purpose by the city or county.