I drive a Crown Vic. at work and the crown vic does the same thing. I asked the mechanic about the issue and he pointed out to me that there was a piece of plastic, some sort of cover in the wheel well, that when you turned sharp and slow enough the tire would catch it and pull it back until it "popped" back into place, I haven't noticed it on my lightning though. Just check the fender well, you should be able to see some wear marks on any of the plastic.