I've thought about letting fly a volley from a paint ball gun.

But, no doubt distracting a driver more than they are would be a bad idea. And, someone would respond with real bullets.

I don't worry much about cars overtaking from the rear. Most of them are travelling slow enough, it is only those that think they're on a closed Indy corse that bother me.

My dreaded pass is the 2 side-by-side cars coming towards me, and the tennis ball won't help a bit.