The AUDI A6 (2004-09) 5DR AVANT 2.7 TDI S LINE is a large, premium diesel estate, offering more load space than the A6 saloon while retaining a smart, executive feel. In the UK used-car market, it sits alongside estate versions of the BMW 5 Series and Mercedes-Benz E-Class, rather than mainstream family wagons. mycarcheck.com checks recorded 173 look-ups covering 80 distinct VINs, a useful snapshot of cars shoppers have researched. Across those records, average private-sale valuation was £1,200, average recorded mileage was 178,000 miles and cars averaged about 10,000 miles a year. The average keeper count was just over five, so checking each car’s history and condition is especially important. Its spacious cabin, boot and diesel performance suit families, commuters and motorway drivers needing luggage room. S line styling gives it a sportier look, while the A6 Avant offers a comfortable, understated alternative to rivals; age and mileage make checks important.