Who is at fault when you open your door in a parking lot and another car runs into it?

Answer

If you were parked and you were exiting the vehicle (car not in motion), the other car is At Fault. A parked car with door open or closed is still a parked car.

This MIGHT be a comparative negligence incident in which both of you may share fault. It depends on several factors: Was your door open all the way before the vehicle drove in? Did you open it the moment the car drove through? Was EITHER party paying attention?