I'm considering getting an A6, 2001-2004 range, 3.0 or maybe 4.2. What should I be looking out for? avoiding?

This is a fantastic forum by the way. Others don't have near the traffic.

 

As far as maintenance wise, the 3.0 and the 4.2 are basically the same. They are both easier (and cheaper) to maintain than the 2.7T. I would start by checking the maintenance history of whatever one you want and obviously, try to get one that was regularly maintained. In my opinion, you probably shoud be looking at 2.7T's or 4.2's, trying to decide between the two of these. The reason being is the performance of these two are very close where as the performance between the 4.2 and 3.0 aresort of far apart. Basically, you're talking two "different" vehicles when you compare the 4.2 and the 3.0.

 

Go for the 4.2, it has performance without the headaches of a 2.7T.

 

From what I've been reading, I would agree. I havent had any real problems with my 2.7T but I've had it for less than a year. The 4.2 has been rock solidsince it was new.