oh btw get a couple of three inch bolts. screw on a few nuts. when you have someone on your rear, try to get to the right of lane and drop them out of driver's window;

old biker trick... I always have them in my vest

 

Thats gnarly!

However, I was just thinking an electric dump valve on the air tank might give em a nice rattle.

Imagine your stopped at a light and suddenly the truck in front of you lets out a giant fart "PSSHHHHHHHHHHHHHHHHHHHHHHH". Ha, Ha. Not too sure about the legality of such a stunt. But a fun idea, none the less.