I had a Cadillac Dealer cut me a new key for my lost 2004 xlr rear key cylinder lock. The new key cut from the vin code does not turn the lock?? The dealer is telling me they will need to replace the rear key cylinder at a cost of @ 1000$ They are telling me that the key code may be wrong??? I am asking for help as a new key is @ 8$. Has anyone had or seen this problume?? Thanks DP