Any self-propelled vehicle used to sell ice cream, snacks and similar products at retail directly from the vehicle in residential neighborhoods shall be equipped with a device or devices, of a type approved by the Superintendent of State Police, in good working order, that, whenever the vehicle is operated in reverse gear, automatically display a light signal and emit an audible alarm signal. The provisions of this section shall not be construed to authorize such vehicles to be equipped with red, blue, or amber warning lights unless authorized under Article 3 (§ 46.2-1010 et seq.) of this chapter. The provisions of this section shall not apply to vehicles commonly known as “concession trailers,” “special events trailers” and similar equipment used to sell or dispense food, soft drinks, bottled water, fruit drinks, wine or malt beverages directly to consumers.