It’s just gravity. When parked on curb, the left side of the car is a bit higher than the right. When the car is unlocked, the latch completely opens and the force of the door opening without a latch holding it enablesthe door to swing free. It depends on how much the latch releases. Usually the latch doesn’t completely let go and the door is just ajar. Other times it releases and there is not enough force to open it more than a couple of inches. But I have had the rear passenger door swing wide open a couple of times. Right now though, the rear passenger door is stuck and I cannot open it from the outside. The front passenger door will crack open most of the ice when I unlock the doors. Very frustrating. I also have the ongoing break light malfunction and the car not recognizing the key fob while driving and asking for a PIN.