This problem only occurs during the winter time. I have tried using three in one oil on the key and seemed to help some but did not entirely get rid of the problem. If the car gets warmed up after 15-25 minutes with the heater on it corrects the problem. Once the car cools back down the problem comes back. You have to wiggle the key in the lock and eventually it will come out. Brute force does not work. The problem was present when the car was new and my car is now 9 years old with 83,000 miles on it and the problem remains about the same. It is just annoying.