2020 Mercedes-Benz GLS 2.9 GLS400d AMG Line Premium Plus

Overview

• Make: Mercedes-Benz
• Model: GLS
• Trim: AMG Line Premium Plus
• Version: 2.9 AMG Line Premium Plus Auto 4WD Euro 6 5dr (325 bhp)
• Year: 2020
• Mileage: 64,643 miles
• Fuel: Diesel
• Body: SUV, 5 doors, 7 seats
• Engine: 2.9 litres, 325 bhp
• Gearbox: Automatic
• Drive: Four-wheel drive
• Colour: Blue
• CO2: 208 g/km
• Emissions standard: Euro 6, ULEZ compliant

About this car

At 64,643 miles, this 2020 Mercedes-Benz GLS AMG Line Premium Plus has covered about 4,100 more miles than other 2020 Mercedes-Benz GLS cars. Its asking price of £42,500 is £239 below the AskCar estimate of £42,739. The AskCar estimate draws on 143 Mercedes-Benz GLS adverts across the UK, adjusting for age, mileage, trim, engine and other specifications. Since we first spotted the advert 82 days ago, the asking price has dropped by £4,150. According to the government's MOT record, its advertised mileage is consistent with the latest test. The seller is Sytner Select Northampton, based in Northampton. How to contact the dealer and its opening hours are on this AskCar page.

Stock data as of 8 November 2026.

How we estimate prices and check cars

Price

Fair price: £239 (under 1%) under the AskCar estimate of £42,739.

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 143 priced Mercedes-Benz GLS adverts across different ages and specifications, as of 8 November 2026.

A 2020 Mercedes-Benz GLS with the 2.9 diesel engine is typically advertised at £45,400: the median of the 12 for sale on AskCar, as of 8 November 2026.

Time on sale

This 2020 Mercedes-Benz GLS has been on sale for at least 82 days.

Price history

AskCar first saw this advert on 18 August 2026 at £46,650. Its asking price is now £42,500, £4,150 less. The latest price cut was seen on 29 October 2026.

Price changes recorded:

• 18 August 2026: £46,650
• 17 September 2026: £45,900
• 26 September 2026: £45,400
• 8 October 2026: £44,400
• 16 October 2026: £43,750
• 22 October 2026: £43,250
• 29 October 2026: £42,500

Mileage and MOT

MOT, from the government's MOT records (DVSA, the Driver and Vehicle Standards Agency), as of 8 November 2026: valid until 2 July 2027.

It has had 4 MOTs. The latest, on 30 June 2026, passed.

There were no advisories at the latest test.

Mileage at that test: 64,064 miles, which matches the advertised 64,643 miles.

Advertised mileage is about 4,100 miles higher than the median mileage of a 2020 Mercedes-Benz GLS on AskCar.

Similar cars

5 other 2020 Mercedes-Benz GLS AMG Line Premium Plus 2.9 diesel automatic SUVs are for sale at UK dealers, from £43,000 to £49,950, as of 8 November 2026.

The 3 closest to this car in mileage:

• 2020 Mercedes-Benz GLS AMG Line Premium Plus, 2.9 diesel SUV, grey. Mileage: 66,681 miles. Price: £43,000, £500 more than this car. Dealer: Saxtons.co.uk in Chelmsford. AskCar page: https://askcar.co.uk/car/mercedes-benz-gls-2020-420eb62b643e
• 2020 Mercedes-Benz GLS AMG Line Premium Plus, 2.9 diesel SUV, black. Mileage: 61,138 miles. Price: £46,995, £4,495 more than this car. Dealer: Mercedes-Benz South West Mercedes Benz Of Exeter in Exeter. AskCar page: https://askcar.co.uk/car/mercedes-benz-gls-2020-c549e2f61aa1
• 2020 Mercedes-Benz GLS AMG Line Premium Plus, 2.9 diesel SUV, grey. Mileage: 60,000 miles. Price: £46,989, £4,489 more than this car. Dealer: Blackstone Motors in Brent. AskCar page: https://askcar.co.uk/car/mercedes-benz-gls-2020-1986b3dd238f