Ok, a week ago the battery in my 2003 CTS went bad. It sat for a few days, then I went out to the car and put in the key. The key got stuck and would not come out. I put the new battery in and the key still wouldn't come out. The car would start but would not go into gear and the key was stuck! After disconnecting and reconnecting the battery, it was ok. So now, a week later, it has done it again, but I can't get it to stop doing it. The anit-theft system says it needs service, they key is stuck in the ignition, and it won't go into gear. It will start thought. Please help, any information is greatly appreciated.