We've been using a C5 S6 Avant as our family vehicle for the past 2.5 years and it's been an outstanding vehicle. I found one with really low mileage and spent quite a bit of effort refurbishing the 13 year old suspension (control arms, dampers, bushings, spring seats, rear springs, etc) in addition to basic maintenance and a TB job. However, we now have a very comfortable car with a ton of cargo space that has a 340hp v8 and is unstoppable in the snow. I had Daz (RIP) tune the TCU, which made a huge difference in shift quality. It still makes me smile every time I drive it.
edit: Forgot to mention how well it tows a trailer with its nice torque curve and relatively short gearing. Not that I tow a huge boat or anything, but it will pull a loaded large utility trailer like it's not even there.
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