Usage of neon underglow lighting is governed by Maine Revised Statutes, Title 29: Motor Vehicles and Traffic, Chapter 17: Equipment, Subchapter 1: General Provisions.
Is neon underglow legal in Maine?
Neon underglow is illegal in Maine, and the law concerning it is very specific and restrictive.
Based on the following excerpt from Maine laws, you are not allowed to display neon underglow on public streets or while driving:
[…] A vehicle may be equipped with under-vehicle lighting for the purpose of participating in shows, events or other exhibitions, but the lighting may not be used or the vehicle illuminated with under-vehicle lighting on a public way.
Car underglow can legally be used for shows or exhibitions, but make sure you never use it while driving. Additionally we don’t recommend using it on public parking lots either, as an over-eager police officer may still be able to give you a citation.
Furthermore such underbody lights may only display white or amber on the front, amber on the side, and amber or red in the rear of the car. Lights may not rotate or flash in any way.
As defined by law auxiliary lights are in fact additional headlamps and fog lights; Maine however puts undercarriage lights within the same category which may restrict colors to the above. In case you never intend to use car underglow in public you may be able to use any color, but use at your own risk.
Maine vehicle lighting laws
Below are all relevant excerpts from Maine Vehicle Code that limit, restrict or allow certain aftermarket lights to be installed on vehicles.
§1909-B. Optional auxiliary lighting
2. Color. The color of an auxiliary light must be as follows:
A. White or amber if the light is on the front of the vehicle;
B. Amber if the light is on the side of the vehicle; or
C. Amber or red if the light is on the rear of the vehicle.
3. Beam. An auxiliary light must emit a steady beam of light and may not blink, oscillate, rotate or flash.
4. Brightness. An auxiliary light may not emit a beam that is brighter than, has a greater candlepower than or distracts from the visibility of standard lighting equipment required by this Title or by the inspection rules adopted by the Chief of the State Police pursuant to section 1769.
5. Operator visibility. An auxiliary light may not be installed in a manner or on the vehicle so that it distracts or impairs the vision of the operator.
6. Under-vehicle lighting. An auxiliary light is under-vehicle lighting if it is a lighting device or lamp, including, but not limited to, a neon or fluorescent tube, installed under the chassis and it is designed to illuminate and reflect from the surface beneath the vehicle. A vehicle may be equipped with under-vehicle lighting for the purpose of participating in shows, events or other exhibitions, but the lighting may not be used or the vehicle illuminated with under-vehicle lighting on a public way.
Penalties
§1909-B. Optional auxiliary lighting
[…] 7. Violation. A person who operates a motor vehicle equipped with, illuminated by, displaying or using an auxiliary light in violation of this section commits a traffic infraction.
