A friend of mine has an '02 A6. He drove to work yesterday and when he went to get in to start it again, the key went through all the detents and start poison like nothing was there. We replaced the ignition switch and put it back in with no improvement. So, I plugged all the important stuff back in, minus the air bag, and put the key in the ignition and used a flat head to turn the switch. The car started fine. My thought is the problem lies in the ignition lock. When I turn the key, the tab on the other side does nothing. There is tons of play in it, and you can spin it by hand with no effect on the key.