I want to buy two and install one in the front of my car on the dash, and another facing out my back window.
The front will say "Move Over!" (for those old people in the fast line going 10 mph below the speed limit)
and
The back one will say "Learn to Drive!"
It would be awesome if you could store like 10 preprogrammed messages in there, then you could communicate to other drivers, effectively conveying your 'feelings' on their driving abilities.