Ever wonder how researchers in the realm of higher education spend their time? This one guy in Colorado (Colorado State University social psychologist William Szlemko) somehow found a correlation between bumper stickers and road rage. For example, the more bumper stickers, decals, etc you have on your car... the more likely you are to... umm... stick it to someone on the road (sorry, couldn't resist).
Now, Mr. Szlemko found it didn't matter what these bumper stickers said... which is rather humorous to me. Of course it's easy to visualize (and stereotype) the car plastered with such things as "my kid beat up your honor student" or "get in, sit down, shut up and hang on" driving by you at break-neck speed on the 101, the driver giving you the death look because you are only going 5 miles per hour over the speed limit, thus slowing him (or her-let's be fair here) down.
But, imagine one of those sleek, environmentally-friendly cars with such slogans as "peace please" or something even more warm and fuzzy stuck on the back bumper ("I brake for ponies and unicorns" or "hug a saguaro"... whatever, I don't know, but you get the picture). Imagine that nice car, with the assumed nice driver inside who just wants world peace. Now, imagine that driver roaring past you on the same stretch of the 101. Sure, you're only going 70mph... but did that driver really have to roll down the window and salute you? Or, was she (or he) telling you that they're number one? You get the picture. It's offensive. Actually, it's a picture I have very clearly in my head. Except it wasn't the 101 I was driving on... it was the I-10. As a side note: I didn't know a Prius could go that fast. Perhaps, sir or madam if you're reading this, when driving at illegal speeds, it would be a little better to keep both hands (and all ten fingers) on the wheel.