2021 Audi A4 Avant S Line prices

There are 28 used 2021 Audi A4 Avant S Line cars for sale from UK dealers on AskCar, as of 10 November 2026. Typical asking price £18,000 (the median: half cost less, half cost more). The cheapest is £8,999. The middle half are priced between £16,400 and £19,200. Median mileage: about 60,000 miles.

Dealers lowered the asking price on more than a quarter of 2021 Audi A4 Avant S Line cars: 9 of the 28 in the 14 days to 10 November 2026.

2021 Audi A4 Avant S Line prices by engine and mileage

EngineAll mileagesUnder 20,000 miles20,000 to 40,000 miles40,000 to 60,000 miles60,000 miles or more
2.0 diesel£18,000Too few for saleToo few for saleToo few for saleToo few for sale

Typical asking prices are of 2021 Audi A4 Avant S Line cars for sale on 10 November 2026, and are given only where at least 20 cars with a price are for sale.

2021 Audi A4 Avant S Line against other years

A 2020 Audi A4 Avant S Line car has a typical asking price of £16,800 and a 2022 one £20,000, as of 10 November 2026.

AskCar lists 1,280 used Audi A4 Avant across the UK, from 848 dealerships.

As of 10 November 2026, AskCar lists 591,054 cars and vans from 12,888 UK dealerships, read daily from dealer websites: over 99% of UK dealer used car adverts. No dealer pays to be listed.

2021 Audi A4 Avant S Line cars for sale now, page 1 of 2

This page picks out up to 10 cars in each of these groups: best value, cheapest, lowest mileage, recently reduced and newly advertised. A car in more than one group is listed in full once. The groups pick only from cars with photos and an AskCar estimate, priced at £500 or more and no more than 25% under that estimate. 26 of the 27 cars listed here meet these rules. Page 2 lists every other 2021 Audi A4 Avant S Line car, cheapest first, including the one the groups do not pick from.

The AskCar estimate is our expected asking price for that one car, from its model, age, mileage and specification, using the 1,227 priced Audi A4 Avant adverts on AskCar as of 10 November 2026. The figures on this page describe the cars advertised, not a valuation of every 2021 Audi A4 Avant S Line.

Each car: year, make, model, engine and trim, power, gearbox, fuel, body, doors, colour; mileage; price and its changes; how the price compares with the AskCar estimate; emissions standard and ULEZ compliance where it holds; MOT; dealer and town; AskCar page. Each car's AskCar page has its full price history and cheaper cars like it.

This list leaves out 1 car whose advertised mileage is lower than the mileage recorded at its last MOT test.

Best value 2021 Audi A4 Avant S Line: priced furthest below the AskCar estimate

These 10 are priced 2% to 13% under their AskCar estimate. Their asking prices run from £17,995 to £22,000.

Cheapest 2021 Audi A4 Avant S Line: the lowest asking prices

These 10 are priced £13,490 to £17,193. They have covered 60,311 to 108,000 miles.

Lowest-mileage 2021 Audi A4 Avant S Line

These 10 have covered 18,925 to 46,478 miles. Their asking prices run from £18,499 to £22,000.

Recently reduced 2021 Audi A4 Avant S Line: the biggest price reductions in the 14 days to 10 November 2026

The dealer lowered the asking price on each of these 8 in the 14 days to 10 November 2026. Their reductions since AskCar first saw them run from £98 to £3,000.

Newly advertised 2021 Audi A4 Avant S Line: first seen by AskCar in the 7 days to 10 November 2026

These 4 are the most recently advertised. Cars first seen on the same day are listed cheapest first.

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