Holy expensive repairs Batman! - But decent car

I have owned this car for about 6 months now. I bought it used online thinking that I was getting a good deal. This car has good and bad in it almost like a love/hate relationship. Please see below for full review:

Reliability: C+ So far the car has started every time. It doesn't discriminate in extreme hot or cold weather, which is obviously good. However, the "Check Engine" light comes on every now and again. The mechanic says that it is just a system flaw. By the way, I know my mechanic on a first-name basis now that I bought this vehicle.

Driving Comfort: A- This car is actually very pleasant to drive. The seats are decorated in fine leather and the electronic functions give you multiple comfort options. The vehicle handles extremely well around corners at higher speeds and the suspension is quite tight. The minus is due to the lack of acceleration off the line.

Curb Appeal: B The car is quite attractive and has a sporty design, especially for a 4-door sedan.

Practicality: D The worst part about the vehicle is the expensive maintenance. The person who sold me the car conveniently failed to tell me that the air conditioning compressor was dead. That only cost about $2,400 to replace. The ridiculous car washer pump also broke - $150. So if you like Audi's, which most people do, the way to go is buy or lease brand new and stay under the warranty. Once you're dumped by the warranty, dump the car.