One for the brains trust please. Car A is parked in a 90degree carpark, in the lines, carB turns into the empty carpark next to it as car A rear door is opening and collects the end of open door just in front of the mirror on the carB passenger front door, leaving a nice 12cm long by 1cm deep ding in car B passenger front door and some scratches on the left side mirror. CarA is a 15 year old ford that looks like its been in a few minors, car B is a 2010 Kia that looks like it was washed last week.. Who's at fault? Car A passenger that opened the door? Car B driver for hitting a parked car?