Bought a CERTIFIED pre-owned Audi A6 at a dealer in Southern California. After about a week I started hearing squeaking noise when I make a full turn. Does not happen very often but when you drive the whole day you hear the squeaking noise from time to time when you are parking and reverse out of a lot. Had brought my A6 to 4 different Audi dealerships for inspection but none of them had a clue where the noise is coming from. One dealership repacked and resealed my front calipers but was still making the noise. The other 3 dealers could not even diagnose the problem. Until now I still have the same issue and its embarassing when you hear the noise when you park and people are near the vehicle and look at my car.