Where to start ? Bought a 2001 A6 avant in 2006 with 106K on the clock. Car was in very good shape. Within a year started having some issue. Did timing belt replacement which is normal maintenance (about $500 in Audi parts if you do yourself). Have replaced the ABS module, 2 combi (EGR) valves, valve cover gaskets, etc. At 149K had to replace 3 steering arms ($700 at shop). Now transmission is acting up and need to replace at 151K. Still have problems with secondary air system and was told by tech probably carbon build up in intake manifold after all other attempted repairs. Great car to drive but very expensive if you don't do the repairs yourself.
This is our second Audi and like the other one, after 50K we ran into multiple defects (engine failures, electric windows, leaks). Our latest repair at 60K miles, is more than $3K. It's a fun car, but after the free maintenance periods (multiple repairs too, but since it's free maintenance and warranty you tend to brush over these quality issues), the poor quality becomes too much.
Wonderfully smooth car. A treat to drive, both in the city and on the highway. Lots of space for family, a big dog and luggage. For all of our needs, it is a great car. Previously, I had the Audi A4 sports sedan. Likewise, it was a wonderful car.
Exceeds expectations in every manner. I needed a car to accommodate seven of which two are children under six. There is ample room with great responsiveness even when the car is full. The car is reliable. I am bewildered as to why anyone would not consider this car.