The AUDI A4 (2001-05) S4 4DR SALOON 4.2 QUATTRO is a performance-focused, four-door executive saloon: more sporting than an ordinary family car, yet still practical for everyday use. In the UK used market, it sits among premium sport saloons, appealing to drivers wanting comfort and pace in one package. mycarcheck.com records 437 look-ups across 135 VINs, a useful sample of interest in this older S4. The checks show average mileage of 119,000 and annual use of 3,000 miles; owners averaged just over eight previous keepers. The average private-sale valuation recorded was £900, so check any example’s condition and history carefully. Its 4.2-litre engine and quattro four-wheel drive give it a distinctive blend of strong performance and reassuring grip, setting it apart from many BMW 3 Series and Mercedes C-Class rivals. It suits enthusiasts needing four seats and a boot, but running costs and older-car upkeep make a careful inspection essential.