My 99 2.8 Quattro A4 (tryptronic) has slightly more than 50K miles and is suddenly requiring a lot of maintenance. This summer I had the air conditioning replaced ($1800) and now the thermostat is sticking and is being replaced. When in there, the mechanics said the water cooler (?) also needed replacing ($450 plus $128). Even though the car is nearly 6 years old, it still only has 50,000 miles. Is this normal? What should I expect for the next 50,000 miles. I plan to keep this car as long as possible. I love it and until now, it has had no problems. Also, I'm planning to have the car professionally detailed. It is in very good shape with just a few nicks and one unfortunate small dent on the hood. What should I expect to pay for this? Thanks and happy audiing.