I'm new in this forum, hope somebody can help me. I have a 2005 A4 Front trak Audi 1.8T (automatic). I just had my 15,000 scheduled maintenance last April 2007. My current mileage is 13,000 miles. Now my computer is showing "check oil!" What could be the possible problem? One thing, I smelled something was burning when I turned on the heater. I also experienced a vibration. The car was on and still (not moving) while waiting for the traffic lights to go green. My timing belt is not yet change after 2 years. And by the way, the Audi dealer wherein I bought my car (Illinois state) was interested to buyback my car! (I wonder why?) I received this letter a week after I had my scheduled maintenance. Actually, i already received this kind of letter twice!! I purchased this car and it is not a lease. I still have more than one year to go to payoff my car. Is something fishy going on why they want to buyback my car? Hope somebody can help me. Thanks!!!