California Code, Vehicle Code - VEH § 11514

(a) An automobile dismantler's established place of business and such other sites or locations as may be operated and maintained by such automobile dismantler in conjunction with his principal established place of business shall have posted, in a place conspicuous to the public in each and every site or location, the license issued by the department and shall have erected or posted thereon such signs or devices providing information relating to the automobile dismantler's name and the location and address of his established place of business so as to enable any person doing business with such automobile dismantler to identify him properly. Every such sign erected or posted on an established place of business shall have an area of not less than 32 square feet per side displayed and shall contain lettering not less than six inches in height. The sign shall indicate the nature of the dismantler's business by inclusion of “Automobile Dismantler”, “Automobile Wrecker”, “Motorcycle Dismantler”, “Trailer Dismantler”, “Vehicle Dismantler”, or a combination of such designations on such sign.

(b) Any local authority may provide for a sign and lettering smaller than that specified in subdivision (a); however, no local authority shall require a sign to have an area of less than four square feet per side displayed.