Re: Smoked Tail Lights
if the addition of the smoked lenses does not cause the lights to not be "plainly visible" (sounds like an interpretable judgment) at a distance of at least 500 feet, then they would arguably be legal.
(d) Rear Lamps. Every motor vehicle, and every trailer or semitrailer attached to a motor vehicle and every vehicle which is being drawn at the end of a combination of vehicles, shall have all originally equipped rear lamps or the equivalent in good working order, which lamps shall exhibit a red light plainly visible under normal atmospheric conditions from a distance of 500 feet to the rear of such vehicle
. One rear lamp or a separate lamp shall be so constructed and placed that the number plate carried on the rear of such vehicle shall under like conditions be illuminated by a white light as to be read from a distance of 50 feet to the rear of such vehicle. Every trailer or semitrailer shall carry at the rear, in addition to the originally equipped lamps, a red reflector of the type which has been approved by the Commissioner and which is so located as to height and is so maintained as to be visible for at least 500 feet when opposed by a motor vehicle displaying lawful undimmed lights at night on an unlighted highway.
to avoid being hassled, you would best be served by asking the local cops. They are the ones that would be pulling him over. It is their initial interpretation that is going to effect him the most.
I am not an attorney and any advice is not to be construed as legal advice. You might even want to ignore my advice. Actually, there are plenty of real attorneys that you might want to ignore as well.