I’ve just got an A7 bitdi- it’s very impressive. 2015 model. Just a hatchback version of the A6.
Engine sounds ok as it’s got a basic kind of kufatec as standard, and torque is ridiculous. Box is a zf, so it’s bulletproof - no S tronic worries. Google box oil changes around 60k - might be worth doing.
1st/2nd seems to get a bit clunky and confused in stop start traffic sometimes but once it’s going its awesome. Very smooth.
Ideally I’d prefer one that hadn’t been on long life servicing but beggars can’t be choosers! If it’s been serviced every 15-20k it’s probably ok, have read somewhere of a couple of turbos needing replacement though.
Spec is variable- worth finding an old price list and decoding the vin via myAudi or a dealer to work out exactly what options you’re getting.
Very solid cars. Interior is incredibly well built. Mines on 60k and ideally needs front lower arms as the captive bushes are getting clunky on bumps. No other faults ... yet...