Joker, I remember those lights as well. I remember them as being mounted in the center of larger trucks, under the bed. Maybe they were retrofits?
I remember them having a round metal housing and the word "STOP" stenciled on the lens, similar to some of those on eBay.
I always thought they were cool. Granted, as a practical matter, no one is going to read the word "STOP" and then decide to obey. But they are a nice nostalgic reminder of another time in my life.
