The AUDI A4 (2001-05) 5DR AVANT 2.5 TDI 155 SPORT is a five-door estate, rather than a hatchback, offering a useful blend of family-car space and executive-car polish. In the UK used-car market it sits among compact premium estates, with the BMW 3 Series Touring and Mercedes-Benz C-Class Estate as familiar alternatives. With a strong diesel engine and practical load area, the A4 Avant suits families, regular commuters and drivers covering longer journeys who want comfort and carrying capacity. The Sport version adds a more purposeful feel, while the model is known for a composed drive and understated cabin. Against mainstream estates, it offers a more upmarket experience, though age and condition matter greatly when buying. mycarcheck.com records seven look-ups across five distinct VINs, so this is a small sample. The observed average private-sale valuation was £300, with 181,000 miles, 7,000 miles yearly and around six previous keepers in the records.