I think if your parked away from everyone and take up 2 spaces, that is fine. Your not close to anyone, so for anyone to put a note on your car, they had to drive or walk up to your car.
If u take up 2 spaces in a crowded parking lot, that is a no-no, u might get focked up.
Though if I see the appropriate car parked in 2 spaces in a crowded parking lot, I'll be like HELL YEAH!!! That is fine, they deserve it.