I would contact the sales person you bought the car from. Explain your situation and let them know that if the problem is not fixed, you will do everything in your power to keep people from buying cars from his dealership. If there is no responce try the sales manager. Then the owner. When you get the home phone number of the owner of the dealership, they begin to listen. I had a few issues with my used 1998 S70T5(had to change the spark plugs one week after buying the car because it did not run). Once I let the owner of West County Volvo here in St. Louis know about my problems, while he was at home, my problems were taken care of. Play hard ball. You've got a nice, and expensive used car. Would they lay down if you forgot to send a payment?
DO NOT LET THEM WIN!