wrt Audi advice, I had a 2000 V8 powered A6 that I bought in 2008 with 96000 kms (about 58K miles) within a week, a fog-light died ($7 bulb, no big deal) then one of the HIDs died ($200 bulb, $500 ballast, then had to replace the other side bulb as they were diff colours - luckily got it all done as warranty) other than that nothing ever went wrong with it. I was relatively active on the local audi forum and met a bunch of guys who had pretty good reliability records. A friend of mine has a 2002 A6 v6 (non-turbo) and that thing is a POS, he has it in the shop at least twice a year for $3000+ repairs that don't seem to fix anything.
As a side note, the V8 in my A6 drank regular and I averaged 19mpg fuel economy over the length of my ownership. The 1.8T drinks premium and posts the same kind of numbers so will cost you more to drive with less power. That was the reason why I went with the 300Hp V8, that and the widebody, good luck in your search