Kids are not mini-adults, and so you can't reasonably expect adult behavior and impose adult consequences and expect that to work. At 6, my kids were barely discovering that a quarter could get them a gumball from the pretty machine at the grocery store; the concept of adult-sized savings and adult-sized spending is sort of meaningless. So the most likely results of making your child pay for the damage would be (a) zero impact, as the dollars in her bank account are too abstract for her to feel it; or (b) disproportionately huge impact for a careless kid mistake, as she equates taking that money to All The Stuff she wants to get with it.
The other thing is that, at that age, long-term consequences are sort of meh; the kids don't really connect consequences to actions unless it's right in the moment. So she would definitely get "daddy is really mad at me," but she wouldn't make that connection the next time she throws the car door open. With my kids, it's all part of a bigger lesson of "be considerate of people/things around you" -- and it's something I still reinforce, in advance, when we are hauling suitcases through an airport, or pulling into a tight parking space, or when they are walking with a cellphone out, etc.
And when they still screw it up, well, they're kids. Shit happens. Not the end of the world. In the end, they -- and their actions -- are my responsibility until they are grown, and so the consequences of their screw-ups are mine to deal with until that point.
Which, as the parent of a new driver, terrifies the crap out of me, but that's another post. :-)