Faults:

Throttle body fault at 50,000 (intermittent fault).

Water pump went out at 53,000 (warranty repair).

Upper control arm failed around 100,000.

ABS control unit failed at 110,000.

Coolant temp sensor failed at 110,000.

Moonroof opens sporadically (not yet fixed).

LED for trip computer is unreadable (a common problem with Audis).

General Comments:

I love this car! Although I have had to replace parts over the 10 years I have had the car, I expect to have to spend some money to maintain my car. This is the third Audi I have owned, and the next car I buy will also be an Audi.

Some of the comments on here about common failures are valid.

The moonroof problem is annoying, but can be solved with a $90 part.

I replaced the timing belt at 89,000, and will probably replace it again at 170,000. If you replace the timing belt, make sure you replace the coolant thermostat at the same time (you have to remove the timing belt to get to this part).

To resolve the throttle body fault, unplug the battery and leave unplugged for several hours then reconnect. The car will run rough for a few hours, but should return to normal without the check engine light coming on.

I plan to drive my car for another 80-90,000 miles.

Faults:

Oil cooler started to go, putting oil in the water.

Lower joints started to knock (8 of them), which are very costly to replace; £400-800 including parts and labour.

Lambda sensor on its way out (Audi say every 160000).

Rear speakers didn't work.

Flushed the engine, and then it started to burn about 2 litres every 100 miles. Fixed by adding Ametech into the oil (I recommend 100%).

General Comments:

A very reliable car, and you feel top notch and are looked upon as someone with money, even if it is 13 years old.

Terrible fuel consumption about 34 mpg.

No performance whatsoever, but gets better the higher the revs.

In my opinion, a pointless engine, and these 1.6's don't last very long.

Quality is all around you, and you can feel safe too.

A very heavy car, but really good car, but buy the 1.9 TDI 1999 onwards.

Faults:

Misfiring.

ECU computer.

Sun roof opens automatically.

Gas cable broken, caused sudden acceleration.

Cheap interior.

General Comments:

Don't ever buy it.

Faults:

Anything and everything that could go wrong with the engine went wrong; Head gasket, alternator, oil leaks, water pump etc... put more money into fixing it every other week than the whole thing cost.

General Comments:

Interior was nice and comfortable, and had a really nice ride... when it ran.

Handles good in the snow.

Ended up selling this car less than a year later, and bought a 1996 BMW 325i, which currently has 260,000 miles on it, and have yet to have any problems.

Faults:

Fuel pump.

Bottom suspension arm.

General Comments:

Got my Audi; a proud moment. I had always wanted one. Driving home, I thought this is it, what a car; comfort, German quality, it's got it all.

Anyway, went out the next day, take the wife and kids for a run, really to show it off, but it wouldn't start. Phone the AA; it needs a new fuel pump. OK, it got one, Nora Batty, how much, 500GBP fitted.

3 weeks later, driving to work, a big bang; steering wheel about snapped my arm off turning, and in the ditch it went. The bottom arm had snapped. Thought this could only happen to me, but hey, no, after speaking to a few A4 and Passat owners, I'm definitely not alone. Seems to be a problem. The bit that worries me is the day before it happened, we were going down the motorway with the family; what if it had happened then?