Was it the driver who opened their door onto your car? If it was the driver of the other car is responsible and liable for the damge to your car - even better if you have independent witnesses who are willing to give statements as this would be suitable evidence to provide in a small claims court if necessary. Try going through your insurance company first for advice, and if neccesary the cops + get some pictures of the damage.
If it was the passenger, im not so sure, may not be so straight forward as to who is liable - again check with your insurance company mate.
Im sick and f*ckin tired of door bangers in car parks not givin a f*ck about other peoples cars. I take 2 spaces as far away from the store every time to avoid b*stards like that - some people have no respect, they are too preoccupied in their own little world to think about others around them.
Hope you get it sorted mate.