Used car guide

2004 Mazda MX-5: common problems and what to check

What gets flagged at MOT on 2004 Mazda MX-5s, from 2,762 tests in 2025, plus known faults and what to look at before you buy one.

2,762MOT tests in 2025
65%pass first time (all 2004 cars: 58%)
3,700typical miles a year
2.7×the usual rate for suspension arm

What stands out

Parts flagged at MOT more often on 2004 Mazda MX-5s than on all cars registered in 2004.

  • Suspension arm2.7× usual
    Mazda MX-5
    11% All 2004 cars
    4.1%

    Failed outright at MOT: 0.4%, against 0.4% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £120–£180 (one arm) ClickMechanic

    At the viewing: Listen for clunks over bumps and feel for the steering wandering. Worn arm bushes show as cracked rubber near the wheels.

  • Rust in key structural areas5.1× usual
    Mazda MX-5
    7.1% All 2004 cars
    1.4%

    Failed outright at MOT: 4.4%, against 1% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £80–£250 our estimate

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

  • Chassis rust or damage2.3× usual
    Mazda MX-5
    9.2% All 2004 cars
    4%

    Failed outright at MOT: 2.9%, against 1.2% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £150–£1,000 our estimate

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

  • Body structure rust or damage2.4× usual
    Mazda MX-5
    8.2% All 2004 cars
    3.4%

    Failed outright at MOT: 2.4%, against 1% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £150–£1,000 our estimate

    At the viewing: Look underneath and along the sills for flaky rust or fresh underseal hiding it.

  • Exhaust emissions (catalyst)2.3× usual
    Mazda MX-5
    6.1% All 2004 cars
    2.6%

    Failed outright at MOT: 6%, against 2.5% of all 2004 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.

Better than most

Tread depth: 9.2% here, against 18.7% of all 2004 cars. Headlights: 5.1% here, against 13.7% of all 2004 cars.

By area

The share of 2004 Mazda MX-5 MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Suspension
    37% 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
    36% 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.

  • Rust and bodywork
    22% 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.

  • Lights and electrics
    21% 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
    20% 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
    13% 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.

Looking at a Mazda MX-5?

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Other years

YearMOT testsMost flagged
20221,355Tyres 10%
20211,464Tyres 16%
20201,057Tyres 19%
20194,003Tyres 19%
20184,240Brakes 21%
20174,566Brakes 22%
20164,088Brakes 25%
20152,975Brakes 21%
20142,835Brakes 22%
20133,079Suspension 25%
20123,097Suspension 25%
20113,362Suspension 30%
20104,591Suspension 31%
20094,060Suspension 33%
20085,189Suspension 37%
20077,291Suspension 38%
20065,875Suspension 40%
20052,954Suspension 36%
20033,549Suspension 38%
20022,812Suspension 37%
20011,741Suspension 37%
20002,398Suspension 35%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2004 Mazda MX-5s registered in 2004. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score