Yep and an ear piercing horn that goes off in the drivers ear if they get within a certain distance of another vehicle at a certain speed.
I can't stand to be tailgated or have someone come back over in front of me in too short a distance. I have a few interesting things I do in the worst cases. I will not share them here. I don't want to start a new trend.
Oh, go ahead and let us know. We won't spill your secrets. :)