Washington Revised Code Title 46. Motor Vehicles § 46.37.310. Selling or using lamps or equipment

(1) No person may have for sale, sell, or offer for sale for use upon or as a part of the equipment of a motor vehicle, trailer, or semitrailer, or use upon any such vehicle any head lamp, auxiliary or fog lamp, rear lamp, signal lamp, or reflector, which reflector is required under this chapter, or parts of any of the foregoing which tend to change the original design or performance, unless of a type which has been submitted to the state patrol and conforming to rules adopted by it.

(2) No person may have for sale, sell, or offer for sale for use upon or as a part of the equipment of a motor vehicle, trailer, or semitrailer any lamp or device mentioned in this section conforming to rules adopted by the state patrol unless such lamp or device bears thereon the trademark or name under which it is approved so as to be legible when installed.

(3) No person may use upon any motor vehicle, trailer, or semitrailer any lamps mentioned in this section unless the lamps are mounted, adjusted, and aimed in accordance with instructions of the state patrol.