Firestone told my wife that her rear brakes on her 2008 Aveo should be cleaned of dust and adjusted. Is this right? I have never heard of that. Also, my wife is a nurse and it has been bitterly cold here in the midwest. I told her to take along her spare keys, let the Aveo run and then lock it up with the spare set before going into a patients home and her car would be warm for her when she comes back out. Well, she tried it but the doors will not lock with it running. Is there a way to get around this???

Thanks in advance