I've had the car one month, and have had this happen twice now. This morning at 10:47 am I parked the car at a local mall. As we walked away I hit the FOB to lock it and watched the handles retract. I was being careful because we had some valuables in the trunk (laptops). When we returned at 11:37 am there was a guy taking pictures of the car. He told me, "Do you realize your back door is open?" Yes, my left rear door was indeed open, and all four doors had their handles extended. The car was completely unlocked! There is no explanation other than the car unlocking itself and opening the door while unattended. This is actually the second time this has happened to me. The previous time it was the rear right door. Update: Tesla replaced the offending door handles.