[Baz]

I've always had the thought of inventing a device which can relay a few words to someone either in front or behind you while driving.

An electronic sign, if you will.

You could have some default words such as:

"BACK OFF PLEASE"

"COULD YOU GIVE IT A BIT MORE GAS PLEASE?"

"PLEASE MOVE OVER SO I CAN GET BY - THANK YOU."

"HOW ABOUT A TURN SIGNAL NEXT TIME PLEASE?"

I don't know if it would even be a problem with traffic law - it could simply go in the back window or on the front bumper........or you could simply hold it out the window instead of your middle finger for example....