You would not believe how rude some people can be to the handicapped. As one of them, who also has permanent handicapped plates on the car AND a window hanger, I see people all the time try to rush to a handicapped spot who shouldn't be parking in one. If you ask them if they are handicapped (and I do this nicely as sometimes people are in relative's cars and actually are), the ones who AREN'T go all defensive and nasty in a way that's often unbelievable!
I've found this to be the case mostly with younger people. I see them fly into a spot, hop out of the car and run to the store doors. The "excuse" I most often hear is, "I'm just running in for a minute!" No sorry I took the spot you need, no regret or respect. The second one makes me go livid...."You're no better than I am! Get over it, B-tch!" Yup...I actually get that quite a bit. Gee, I wish I WAS better than they are...I could run a freakin' marathon and not hurt or fall over when I walk!