2018 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: 2018
• Mileage: 18,400 miles
• Fuel: Petrol
• Body: Convertible, 2 doors, 4 seats
• Engine: 2.0 litres, 181 bhp
• Gearbox: Automatic
• Drive: Rear-wheel drive
• Colour: Blue
• CO2: 144 g/km
• Emissions standard: Euro 6, ULEZ compliant

About this car

This 2018 BMW 4 Series M Sport is advertised with 18,400 miles, approximately 44,600 below the typical mileage for its age. The AskCar estimate for this car is £18,819. It is priced at £19,950, which is £1,131 above that estimate. The AskCar estimate uses 1,814 UK dealer adverts for the BMW 4 Series, with adjustments for age, mileage, trim, engine and other specifications. We first recorded this car for sale 70 days ago. Its advertised mileage matches the government's MOT record. It is for sale at JS Prestige and Performance in Potters BAR. How to contact the dealer and its opening hours are on this AskCar page.

Stock data as of 4 November 2026.

How we estimate prices and check cars

Price

Fair price: £1,131 (6%) over the AskCar estimate of £18,819.

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 1,814 priced BMW 4 Series adverts across different ages and specifications, as of 4 November 2026.

A 2018 BMW 4 Series with the 2.0 petrol engine is typically advertised at £14,500: the median of the 112 for sale on AskCar, as of 4 November 2026.

Time on sale

This 2018 BMW 4 Series has been on sale for at least 70 days.

Price history

AskCar first saw this advert on 26 August 2026 at £19,950. Its asking price has not changed.

Mileage and MOT

MOT, from the government's MOT records (DVSA, the Driver and Vehicle Standards Agency), as of 4 November 2026: valid until 8 August 2027.

It has had 6 MOTs. The latest, on 31 July 2026, passed.

There were no advisories at the latest test.

Mileage at that test: 18,365 miles, which matches the advertised 18,400 miles.

Advertised mileage is about 44,600 miles lower than the median mileage of a 2018 BMW 4 Series on AskCar.

Similar cars

12 other 2018 BMW 4 Series M Sport 2.0 petrol automatic convertibles are for sale at UK dealers, from £14,489 to £23,995, as of 4 November 2026.

The 3 closest to this car in mileage:

• 2018 BMW 4 Series M Sport, 2.0 petrol convertible, grey. Mileage: 10,000 miles. Price: £23,995, £4,045 more than this car. Dealer: Christchurch Motor Company in Bournemouth. AskCar page: https://askcar.co.uk/car/bmw-4-series-2018-bbf6133f449c
• 2018 BMW 4 Series M Sport, 2.0 petrol convertible, white. Mileage: 28,363 miles. Price: £16,590, £3,360 less than this car. Dealer: Shirlton Car Sales in Cannock. AskCar page: https://askcar.co.uk/car/bmw-4-series-2018-24f01be90652
• 2018 BMW 4 Series M Sport, 2.0 petrol convertible, grey. Mileage: 28,500 miles. Price: £18,265, £1,685 less than this car. Dealer: Cox Motor Group Blackpool Automart in Blackpool. AskCar page: https://askcar.co.uk/car/bmw-4-series-2018-31d6a3327406

• The nearest: 2018 BMW 4 Series M Sport, 2.0 petrol convertible, white, 26 miles from this car. Mileage: 66,207 miles. Price: £14,995, £4,955 less than this car. Dealer: ARJ Motors in Addlestone. AskCar page: https://askcar.co.uk/car/bmw-4-series-2018-97304c10d21d