Sorry but YABU. I'm a non driver, and I fully appreciate how much money, time & responsibility (such as in this case) it takes to run a car. She is doing you all a massive favour, and I'm just going to assume it's far from the first time she's done it.
She absolutely WBU chucking you out of the car at 4am, but then again, maybe she was feeling incredibly hurt & perhaps a little used? I know I'd be very upset about it. Especially since she couldn't go and enjoy the night out and drink herself, she was putting herself out for you. I'm not trying to justify her leaving you there though, it's not on. Neither however, was your behaviour IMO.
Did any of you tell her before leaving the car parked that she was parking inappropriately (you mentioned it was her responsibility for inappropriate parking)? If not, why? If you knew, and didn't tell her that's pretty rotten. If however you were ignorant to it also, then perhaps give her less of a hard time for making a mistake, and make the effort to support her through it.
It sounds as if she's trying to do nice things for her friends, and getting a bit of a slap in the face for it. Regardless of her being responsibly for the mistake, if she wasn't ferrying you all around then she wouldn't be in that situation anyway.
I have to be honest, my friends wouldn't need to ask for the money in the first place, I would offer something towards it just to be a nice friend. Even if all I could afford was a tenner. No way would I have friends ferry me about, and when/if THEY got in a pickle, leave them on their own with it. I think perhaps she's upset at the lack of gesture, not the money.