Or, you could do what I did, and make one of these:
So far, I've had no problems with people anymore. once they read the sticker, they just pass nice and smooth, no flooring it or anything.
Also, makes you not want to speed because you'd be a hypocrite for putting it on but your speeding.. That's what It's doing to me anyway.
I'm gonna make a sticker to put on the drivers side of the bumper that says Pass Here with an <- sign.