1. Ragers. Not known for their apologies. So screw them. They don't need another tool to communicate their rage.

2. Recipients of rage. Is this so they can offer an apology? Surely nobody believes they need to apologize for their driving frequently enough to buy and install such a device. And if they want to respond to the rager with a plausible defense message, well, that's not going to quell a rager!

3. Those who want to broadcast an undirected opinion. Mod the device to bypass the 50 sanitized preset messages and you can show everyone your political beliefs, meme, or pithy quote. So basically dynamic LED bumper stickers. Free speech, fine, but more distraction. Yawn.