Idiots who can't use their headlights on their cars properly

Another thing that irritates me is tossers who insist on using high beam on their cars at night... in an area which clearly doesn't need high beams (most of the country). Idiots! I can see you perfectly well, I don't need people like you to dazzle me from behind! What I want to get is a dot-matrix display for the back window, so that when I'm confronted by idiots like that, I can type in a little keyboard from my wheel, "TWAT!". That'll teach them!