An inordinate number of drivers I've run across recently have their heads up their asses:
Stop signs ARE NOT suggestions.
Emergency vehicles blaring sirens or flashing lights mean you pull to the side of the road, out of their way, IMMEDIATELY. That's why they're called emergency vehicles and why they get to blare sirens and flash lights.
Yellow DOES NOT MEAN speed up.
Don't enter an intersection UNLESS YOU CAN GET THROUGH IT before the traffic light changes. I won't "t-bone" you if you do, but I wish someone would.
Your rear view mirror is not meant for FIXING YOUR MAKE-UP.
Your rear view mirror is not meant for watching your face while you SHAVE YOUR FIVE O'CLOCK SHADOW.
Your windows are transparent. I can see you PICKING YOUR NOSE AND EATING IT, at the stop light. Knock it off. It makes me retch.
If you have to unfold the map you're using, PULL THE FUCK OVER ONTO THE SHOULDER.
If you don't have a left turn arrow, DON'T TURN LEFT IN FRONT OF ONCOMING TRAFFIC.
And for the love of G-d, STOP FLICKING YOUR LIGHTED CIGARETTES out the window. Mostly you're just an asshat litterer. But, once in a while, at highway speeds, you're courting a genuine disaster.
(This last one is the one that prompted this post. A lighted cigarette bounced off my driver's side window on the highway, this morning. Had my window been open, yikes!)