My understanding is federal regulations on automobile safety and visibility. I use it as a tool to identify chebies and mopars, before 68 and 68 and above. :ide fd
Yeah, and you could also use it identify Mustangs before 68 and 68 and above, except for the apparently multitude of 68 owners who don't run with reflectors. :craz
So of course it was federal regulations, as several items changed in 68 due to compliance, but what good is a reflector? They added the marker light to the fender, and there is already wiring right there to the taillights. The question was more along the lines of why didn't they just put a light there instead of a reflector.