Used car guide

2015 Smart (mcc) Forfour: common problems and what to check

What gets flagged at MOT on 2015 Smart (mcc) Forfours, from 5,421 tests in 2025, plus known faults and what to look at before you buy one.

5,421MOT tests in 2025
66%pass first time (all 2015 cars: 72%)
5,300typical miles a year
2.3×the usual rate for ball joint

What stands out

Parts flagged at MOT more often on 2015 Smart (mcc) Forfours than on all cars registered in 2015.

  • Ball joint2.3× usual
    Smart (mcc) Forfour
    8.4% All 2015 cars
    3.6%

    Failed outright at MOT: 5.9%, against 1.9% of all 2015 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.

  • Exhaust emissions (catalyst)8.5× usual
    Smart (mcc) Forfour
    5.1% All 2015 cars
    0.6%

    Failed outright at MOT: 5.1%, against 0.6% of all 2015 cars. The rest were advisories or minor defects.

    Rough price £175–£900 (catalytic converter) ClickMechanic

    At the viewing: Look for smoke when revving the warm engine and for engine or DPF warning lights.

  • Brake lights2.8× usual
    Smart (mcc) Forfour
    6.2% All 2015 cars
    2.2%

    Failed outright at MOT: 6%, against 1.7% of all 2015 cars. The rest were advisories or minor defects.

    Rough price £10–£80 our estimate

    At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.

  • Exhaust system2× usual
    Smart (mcc) Forfour
    5.5% All 2015 cars
    2.7%

    Failed outright at MOT: 2.5%, against 0.7% of all 2015 cars. The rest were advisories or minor defects.

    Rough price £100–£500 (pipe or section) ClickMechanic

    At the viewing: Listen for blowing or rattling from underneath at idle, and look for black soot around joints.

  • Anti-roll bar link joints2.5× usual
    Smart (mcc) Forfour
    3.5% All 2015 cars
    1.4%

    Failed outright at MOT: 1.5%, against 0.5% of all 2015 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.

Better than most

Shock absorbers: 2% here, against 5.2% of all 2015 cars.

By area

The share of 2015 Smart (mcc) Forfour 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.

  • Suspension
    23% 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.

  • Brakes
    22% 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
    15% 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.

  • Exhaust and emissions
    7% 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.

Looking at a Smart (mcc) Forfour?

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Other years

YearMOT testsMost flagged
20191,941Tyres 31%
20183,783Tyres 31%
20174,756Tyres 31%
20165,283Tyres 32%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2015 Smart (mcc) Forfours registered in 2015. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score