Used car guide

2018 Mercedes-Benz A-Class: common problems and what to check

What gets flagged at MOT on 2018 Mercedes-Benz A-Classs, from 40,350 tests in 2025, plus known faults and what to look at before you buy one.

40,350MOT tests in 2025
83%pass first time (all 2018 cars: 81%)
7,700typical miles a year
32%had tyres flagged

What gets flagged at MOT

The share of 2018 Mercedes-Benz A-Class MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    32% of testsRough price £70–£150

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Brakes
    19% of testsRough price £150–£350

    At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

  • Lights and electrics
    6% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Wipers, windscreen and mirrors
    6% of testsRough price £15–£250

    At the viewing: Check for chips in the driver's view, and test the wipers and washers.

  • Suspension
    5% of testsRough price £120–£400

    At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.

  • Seats and seatbelts
    2% of testsRough price £80–£250

    At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.

Looking at a Mercedes-Benz A-Class?

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Other years

YearMOT testsMost flagged
20198,517Tyres 29%
201740,581Tyres 34%
201637,860Tyres 34%
201526,503Tyres 34%
201422,674Tyres 35%
201314,296Tyres 34%
20125,032Brakes 34%
20115,181Brakes 39%
20105,779Brakes 42%
20096,427Brakes 49%
20086,075Brakes 49%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2018 Mercedes-Benz A-Classs registered in 2018. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score