Illuminated stop sign on back of vehicle illegal?

There are alot of idiots on the road who crash into the back of cars that are waiting at red lights (even with all the bright brake lights and all). Is it legal to have an illuminated stop sign on the rear of my car that turns on when I am stopped at red lights? (or even a slow sign that turns on when I am... show more There are alot of idiots on the road who crash into the back of cars that are waiting at red lights (even with all the bright brake lights and all).
Is it legal to have an illuminated stop sign on the rear of my car that turns on when I am stopped at red lights? (or even a slow sign that turns on when I am breaking)

(is "alot" a word?)
5 answers 5