The AUDI A6 (2004-09) 4DR SALOON 2.0 TDI 140 TDV S LINE is a roomy four-door diesel saloon for buyers seeking comfort beyond a family hatchback. In the UK, it belongs to the premium executive-car class, alongside the BMW 5 Series and Mercedes-Benz E-Class. Its styling feels smart, never showy. Mycarcheck.com records 435 look-ups for this model and 197 distinct VINs, a useful sample of cars researched. Checked examples average 165,000 miles and around 6,000 miles of annual use, with just over five previous keepers. The average private-sale valuation is £1,200; condition, history and local prices can vary between examples. The 2.0 TDI suits regular commuters and families wanting a composed long-distance car with a useful boot and S Line’s sportier look. It offers a more substantial, polished feel than mainstream saloons, though age and high mileages make a careful history check important. Best for value-focused buyers comfortable with upkeep.