Your going to get a lot of hate for a VW/Audi on this forum but the truth is when taken car of properly they can be very reliable. You don't see Audi dealers in Germany with their parking lots (or roads) littered with so many broken cars the mechanics cant keep up.
The problem many times is more to do with the owner and maintenance, not you cant run 0w20, PYB, VWB and a cheap filter, Prestone AMM coolant, Supertech ATF and Prestone or Valvoline PS fluid from Wally's, brake pads and rotors from AA and expect it to be fine, it wont be, you can etch that in stone the car will just get worse by the day.
Quality fluid from a company like Pentosin, filters from Mann or Mahle and Castrol 0w40 or Mobil 1 0w40 will go a long way in keeping the drive train in good condition. Use OE or known high quality aftermarket part, like ATE, Textar, Padgid, Mintex, Zimmerman rotors, etc with ATE or Pentosin DOT 4 fluid every 2 years.
Maintenance isn't overly expensive but you need to be conscientious about it.
Remember one cheap cheesy part can negatively effect many others and cause untold grief. I have run some VW/Audi cars over 200K with not much more than a brake job, plugs and wiper blades and routine maintenance.
If you buy one ask before buying parts and fluid if you have questions on how do something with maintenance ask. Bleeding the cooling system is a good example, you hear many folks complaining , calling the car junk and all sorts of stuff because they cant get the air out.
A $79 vacuum tool (that can be used on almost any car also) will do the job for you with no air in a couple of minute, no stress and no bother.