Used car guide

1999 Mercedes-Benz CLK: common problems and what to check

What gets flagged at MOT on 1999 Mercedes-Benz CLKs, from 698 tests in 2025, plus known faults and what to look at before you buy one.

698MOT tests in 2025
68%pass first time (all 1999 cars: 65%)
3,900typical miles a year
2.1×the usual rate for headlights

What stands out

Parts flagged at MOT more often on 1999 Mercedes-Benz CLKs than on all cars registered in 1999.

  • Headlights2.1× usual
    Mercedes-Benz CLK
    12.2% All 1999 cars
    5.9%

    Failed outright at MOT: 3.2%, against 2.8% of all 1999 cars. The rest were advisories or minor defects.

    Rough price £40–£400 our estimate

    At the viewing: Check both headlights on dipped and full beam, and look for cloudy or cracked lenses.

  • Wheel bearings2× usual
    Mercedes-Benz CLK
    11.2% All 1999 cars
    5.6%

    Failed outright at MOT: 1%, against 1% of all 1999 cars. The rest were advisories or minor defects.

    Rough price £120–£300 (one bearing) ClickMechanic

    At the viewing: Listen for a hum or growl that changes as you steer at speed.

  • Side repeaters4.7× usual
    Mercedes-Benz CLK
    5.6% All 1999 cars
    1.2%

    Failed outright at MOT: 2.6%, against 0.7% of all 1999 cars. The rest were advisories or minor defects.

    Rough price £10–£80 our estimate

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

  • Sub-frame2.3× usual
    Mercedes-Benz CLK
    8.2% All 1999 cars
    3.5%

    Failed outright at MOT: 0.1%, against 0.2% of all 1999 cars. The rest were advisories or minor defects.

    Rough price £300–£1,000 our estimate

    At the viewing: Look underneath at the frame the suspension bolts to. Flaky rust or holes are expensive to fix.

  • Transmission oil leaks2.1× usual
    Mercedes-Benz CLK
    4.9% All 1999 cars
    2.3%

    Failed outright at MOT: 0%, against 0% of all 1999 cars. The rest were advisories or minor defects.

    Rough price £80–£600 our estimate

    At the viewing: Look under the engine and where the car is usually parked for fresh oil. Ask whether the leak has been looked at.

Better than most

Chassis rust or damage: 2.9% here, against 5.9% of all 1999 cars.

By area

The share of 1999 Mercedes-Benz CLK MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Suspension
    38% 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
    38% 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
    36% of testsRough price £10–£80

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

  • Tyres
    28% 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.

  • Oil and fluid leaks
    18% of testsRough price £80–£600

    At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

  • Rust and bodywork
    10% of testsRough price £150–£1,000

    At the viewing: Check the sills, wheel arches and underneath for rust, and look along the panels for uneven gaps or paint.

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Other years

YearMOT testsMost flagged
20092,745Suspension 46%
20082,454Suspension 48%
20073,399Suspension 50%
20062,832Suspension 47%
20053,419Suspension 48%
20043,442Suspension 49%
20032,433Suspension 45%
20021,331Brakes 42%
20011,121Brakes 37%
2000949Brakes 40%
1998186Suspension 38%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 1999 Mercedes-Benz CLKs registered in 1999. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score