How long have you had it?
Hartster had this one before me and had effectively installed UrS4 suspension so it handles well for a big machine. It's funny,for an old car (and mine has a few cosmetic warts), it's still great to drive and dynamically quite different to the fwd one I owned before this one. Not quite as much get up and go but it sticks to the road.
I brought it as my first car. Had it for nearly two years now, Learned to drive in my Dads Audi 80, when i looked for a car I was seriously disappointed test driving the typical first car(Toyota corollas etc ) so i brought the A6. Financially a bit stupid cause it sure likes a drink

Handling wise it is a barge if pushed too hard, but it always seems to hang on. As for the engine, its pretty slow of the line, but open road its not bad, i usually trip the 140km/h GPS speed warning when overtaking, can actually be quite surprising. Mine does have a few dings and scratches. Most of which was done by the previous owners, I did smack into the back of a peugeot pretty hard driving home from work one day, Only put a minor crack in the bumper.
I was kicking myself when i missed an A6 Avant at turners, Had the 30V 2.8 motor, quattro, auto and 130k kms. I think it went for just over $4k