Used car guide

2018 Smart (mcc) Forfour: common problems and what to check

What gets flagged at MOT on 2018 Smart (mcc) Forfours, from 3,783 tests in 2025, plus known faults and what to look at before you buy one.

3,783MOT tests in 2025
79%pass first time (all 2018 cars: 81%)
4,900typical miles a year
1.9×the usual rate for ball joint

What stands out

Parts flagged at MOT more often on 2018 Smart (mcc) Forfours than on all cars registered in 2018.

  • Ball joint1.9× usual
    Smart (mcc) Forfour
    2.5% All 2018 cars
    1.3%

    Failed outright at MOT: 1.4%, against 0.6% of all 2018 cars. The rest were advisories or minor defects.

    Rough price £60–£150 (one joint) ClickMechanic

    At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

By area

The share of 2018 Smart (mcc) Forfour MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    31% 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
    20% 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
    9% 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
    8% of testsRough price £15–£250

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

  • Suspension
    7% 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.

  • Exhaust and emissions
    2% of testsRough price £100–£1,200

    At the viewing: Look for black soot in the tailpipe, listen for blowing from the exhaust and check for engine or DPF warning lights.

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Other years

YearMOT testsMost flagged
20191,941Tyres 31%
20174,756Tyres 31%
20165,283Tyres 32%
20155,421Tyres 32%

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