While Christine is scary, when you think about it, it wouldn't really be all that hard to get away from her, or at least get to where she can't touch you. Seriously.
If I was Moochie in that situation, I would have stood my ground. I would have just ducked in and out between those concrete pillars she was parked by. While she's an evil car and can self repair, she can't turn on a dime, so just keep moving and let her bash into them for a while.
If that didn't work, I'd just keep hopping over the guardrail. She can't crash through it, so she'd have to keep going all the way around to be able to take another swing at you.
He also passed a couple of concrete retaining walls that were several feet high. Just jump on one of them and again, let he bash away to her hearts content.
Getting away from an evil car isn't that hard if you just think about your options.