Once again, xkcd is made of win:
I loathe people who think they are so much more important than the rest of us that they're entitled to two spaces. When I come across a diagonally parked sports car, I park my dirty beat-up old car next to it as close as I can. I did that for a week solid at the office at my job about a dozen years ago; after a few days we had a whole line of cars parked diagonally.