I love my little Civic, but I know what you mean! I have seen some ahhh...hmmm, how to say it...."well decorated" ones??
Anyway, the slow drivers in the left hand lane bug me, and the lack of turn signal. My dad rarely uses the blinker, and it drives me nuts when I'm in the car. I'm a compulsive turn signal user.
People who are flying down the road while you are waiting to turn are fine, because you wait until they pass and turn. However, it's the people who all of a sudden drop their speed to about 25 miles an hour about 30 yards before they get to where you are, therefore you really could have gone...but by that point the other oncoming traffic is coming and you're stuck for longer.
I don't think I have road rage exactly, but I am so the girl who yells to myself in the car at other drivers on the road. No one is ever in the car with me of course when it happens, so I just look pretty dumb. I feel better afterwards though.