2021 BMW 4 Series 2.0 420i M Sport

Overview

• Make: BMW
• Model: 4 Series
• Trim: M Sport
• Version: 2.0 420i M Sport Auto RWD Euro 6 (s/s) 2dr (181 bhp)
• Year: 2021
• Mileage: 33,000 miles
• Fuel: Petrol
• Body: Convertible, 2 doors, 4 seats
• Engine: 2.0 litres, 181 bhp
• Gearbox: Automatic
• Drive: Rear-wheel drive
• Colour: Green
• CO2: 160 g/km
• Emissions standard: Euro 6, ULEZ compliant

About this car

This 2021 BMW 4 Series M Sport is advertised with 33,000 miles, approximately 11,100 below the typical mileage for its age. The AskCar estimate for this car is £25,198. It is priced at £25,990, which is £792 above that estimate. The AskCar estimate draws on 1,833 BMW 4 Series adverts across the UK, adjusting for age, mileage, trim, engine and other specifications. We first saw this car advertised 75 days ago. Its asking price has since fallen by £3,000. The recorded MOT expired on 7 September 2026, so ask the dealer whether it has been renewed. We checked its advertised mileage against the government's MOT record, and they match. It is advertised by Northover Cars in Whitstable. How to contact the dealer and its opening hours are on this AskCar page.

Stock data as of 5 November 2026.

How we estimate prices and check cars

Price

Fair price: £792 (3%) over the AskCar estimate of £25,198.

The AskCar estimate is our expected asking price for this car. It uses UK dealer asking prices, accounting for make, model, trim, version, age, mileage, fuel, gearbox, body type, driven wheels, engine size and power. It is an advertised price, not a confirmed sale price.

It draws on 1,833 priced BMW 4 Series adverts across different ages and specifications, as of 5 November 2026.

A 2021 BMW 4 Series with the 2.0 petrol engine is typically advertised at £24,000: the median of the 149 for sale on AskCar, as of 5 November 2026.

Time on sale

This 2021 BMW 4 Series has been on sale for at least 75 days.

Price history

AskCar first saw this advert on 22 August 2026 at £28,990. Its asking price is now £25,990, £3,000 less. The latest price cut was seen on 29 October 2026.

Price changes recorded:

• 22 August 2026: £28,990
• 3 September 2026: £27,990
• 29 October 2026: £25,990

Mileage and MOT

MOT, from the government's MOT records (DVSA, the Driver and Vehicle Standards Agency), as of 5 November 2026: the latest record we hold ran out on 7 September 2026; ask the dealer for the current MOT.

It has had 3 MOTs. The latest, on 8 September 2025, passed.

There were no advisories at the latest test.

Mileage at that test: 24,057 miles, which matches the advertised 33,000 miles.

Advertised mileage is about 11,100 miles lower than the median mileage of a 2021 BMW 4 Series on AskCar.

Similar cars

26 other 2021 BMW 4 Series M Sport 2.0 petrol automatic convertibles are for sale at UK dealers, from £18,990 to £33,950, as of 5 November 2026.

The 3 closest to this car in mileage:

• 2021 BMW 4 Series M Sport, 2.0 petrol convertible, white. Mileage: 33,078 miles. Price: £27,495, £1,505 more than this car. Dealer: Vines of Guildford BMW in Guildford. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-e16967b0feee
• 2021 BMW 4 Series M Sport, 2.0 petrol convertible, white. Mileage: 33,607 miles. Price: £24,850, £1,140 less than this car. Dealer: Evans Halshaw Vauxhall Newport in Newport. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-b45f7103a93e
• 2021 BMW 4 Series M Sport, 2.0 petrol convertible, white. Mileage: 35,008 miles. Price: £25,990, the same price as this car. Dealer: Alpha Motors in Wigan. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-dfd9ebfe4c58

• The nearest: 2021 BMW 4 Series M Sport, 2.0 petrol convertible, white, 22 miles from this car. Mileage: 58,943 miles. Price: £22,990, £3,000 less than this car. Dealer: Group 1 Southend BMW in Southend-on-Sea. AskCar page: https://askcar.co.uk/car/bmw-4-series-2021-088e831a7c9e