Used car guide

2006 Smart (mcc) Forfour: common problems and what to check

What gets flagged at MOT on 2006 Smart (mcc) Forfours, from 378 tests in 2025, plus known faults and what to look at before you buy one.

Small sample: only 378 of these were MOT tested in 2025, so treat the percentages as rough. The known faults below don't depend on it.

378MOT tests in 2025
56%pass first time (all 2006 cars: 57%)
5,000typical miles a year
2.2×the usual rate for track rod ends

What stands out

Parts flagged at MOT more often on 2006 Smart (mcc) Forfours than on all cars registered in 2006.

  • Track rod ends2.2× usual
    Smart (mcc) Forfour
    12.4% All 2006 cars
    5.7%

    Failed outright at MOT: 6.6%, against 2.4% of all 2006 cars. The rest were advisories or minor defects.

    Rough price £50–£150 (one end, plus about £30–£50 if it needs a wheel alignment) ClickMechanic

    At the viewing: On a straight road the steering wheel should sit straight. Listen for knocks when turning, and check the steering feels even.

  • Ball joint dust cover2.2× usual
    Smart (mcc) Forfour
    10.6% All 2006 cars
    4.9%

    Failed outright at MOT: 3.7%, against 2% of all 2006 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.

  • Anti-roll bar link joints2.1× usual
    Smart (mcc) Forfour
    8.7% All 2006 cars
    4.2%

    Failed outright at MOT: 1.6%, against 1.5% of all 2006 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

Engine oil leaks: 5.3% here, against 13.7% of all 2006 cars.

By area

The share of 2006 Smart (mcc) Forfour MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Lights and electrics
    47% of testsRough price £10–£80

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

  • Suspension
    47% 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
    31% 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.

  • 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.

  • Wipers, windscreen and mirrors
    13% 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
    11% 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%
20183,783Tyres 31%
20174,756Tyres 31%
20165,283Tyres 32%
20155,421Tyres 32%
2005459Suspension 52%
2004167Suspension 52%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2006 Smart (mcc) Forfours registered in 2006. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score