I will have had this car for 5 years (117,000 miles) this February. I was going out for new years eve and wanted to preheat the car. The car was plugged in to a L2 charger in my garage. I started the car still plugged in, set the climate and left the key in the center console. I was planning on preheating for 10 minutes but it ended up around 15 minutes. When I went to leave the car was locked. I tried to use the spare key to unlock the car with no luck. I then used the on-star app on my phone and that worked. I have preheated the car like this many times (100 plus) with no problem. This was probably one of the longest preheat times. After I unlocked with the app I though it was probably easier and faster if I just used the manual key. I would have had a problem if my wife was out with the other key and I put my iphone in the car as well. I have done that exact scenario but never had the car lock.