This issue started in March 2015. We were on a vacation far from home. We were at a gas station getting fuel. When my husband tried to get back into the car the driver door would not open at all. We tried everything we could think of to get the door to open. Finally, he crawled in through the passenger door. At our next stop the door would not open and he crawled back out through the passenger door. This is no small feet for a 70 year old that has major back problems. We called AAA not knowing what this issue could be. They could not figure it out either. Then, all of a sudden the door opened. This happened several times on the same trip. When we returned home we had the door locking mechanism replaced for $250. Several months later the same thing happened with the passenger door. Another $250. The dealer and GM said they had never heard of the problem. Apparently, according to GM we are the only car in North America that has ever had this issue. I considered this a major safety issue and to this day can not figure out why this is not a recall. Now, we are in April 2016 and both of the rear doors will lock/unlock automatically sometimes. We can lock/unlock them manually but this is becoming a real pain. We don't want to pay another $500 to have them fixed so will live with the problem as long as we can. Seriously considering getting rid of this vehicle. We have been GM customers for many years.