I wonder if anyone who's into slapping the trunk or whatever part of the car as it passes have ever tried this: almost get clipped, slap the car really hard, then fall over behind the car, screaming, as if in pain. This way, when they keep driving, you can grap the licnce plate number, and report them/find out where they live, - or - if they stop, you can thrash about screaming, "My leg!" for a few seconds, then, jump up, and in your best announcer's voice, say, "This is a test. This is only a test. If the event that you actually take someone out in your incompetence, this display would be followed by important news and lawsuits. This has been a test of the Jackhole Cager Monitoring System."

Anyone ever done that? No? Pity.