Has anyone had one of these? What are they like and how do they compare to the non-quattro. Also what are the best options to look for on an A4 avant TDi and finally, what sort of mileage are they capable of doing and what big items go wrong (suspension, brakes, engine, gearbox etc) and at what mileages? Sorry for all the questions but I'm thinking of selling my 1997 A6 1.8T and getting either the tdi quattro or non quattro version of the above of about the same vintage. Thanks.