Go for the Audi, the VW will be fine as an every day car, but will be gutless when towing.
diver: Try looking at a Passat TDI 4Motion - I've had two now they pull very well and have haldex 4x4 same as audi quattro with very good fuel cosumption too.
Not quite. Don't get me wrong, the VW 4Motion is a damn fine car, same space as an A6, more rear legroom, more boot space, a refined and comfortable drive in SE specification, and probably better fuel consumption overall.
Hadlex is part-time 4WD and kicks in when wheels lose traction? Primarily it's front wheel drive the rest of the time. Same as Audi TT and A3 quattro or S3, etc.
Only A4, A6 Q5, Q7, etc, are permanent 4 wheel drive and authentic quattro.