All generations and engines together · 41,937 MOT tests in the 2025 data · typical mileage at age 7: 33k
Split by first-registration year. Cars registered in a changeover year can belong to either generation.
Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.
Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.
The rows that judge the model rather than its keeper. 16,214 tests in this band.
Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.
Owner folklore from forums and the motoring press. Most of it never shows up in an MOT, which is why this section exists at all.
Early cars (NA and NB, roughly pre-2005) rot from the inside at the sills, rear wheel arches, front subframe mounting points and the door drain holes, areas hidden under plastic trim so the damage builds unseen. Owners on the MX-5 forums report holes appearing in these box sections once cars get into their late teens or twenties in age. A proper sill repair runs from around £500 up past £3,000 if the subframe mounts are involved, and there's no recall for it, it's just how the shell ages in UK winters.
NA and NB cars (up to around 2005) use a timing belt rather than a chain, and the 1.6/1.8 engines are interference designs, so a snapped belt bends valves and can write the engine off. Mazda's interval is 5 years or 60,000 miles, whichever comes first, but plenty of used examples turn up with no paperwork proving it's ever been changed. A belt and water pump job done properly is roughly £300-500; a wrecked engine from a snapped one is a different order of cost entirely.
A well-known NB trait: the crank angle sensor overheats and cuts out, so the car simply dies and won't restart until it cools down, often mistaken for a flat battery or empty tank. Coil packs, especially on the 1.8, fail separately and cause misfires and rough running under load. Neither shows up at an MOT since the car can run fine cold on the day. Parts are cheap, roughly £100-300 for a sensor and £50-200 for a coil pack, but the intermittent nature makes them a pain to chase down.
The fabric roof wears through at the fold lines and the plastic rear screen goes cloudy and brittle with age and UV exposure, eventually letting water in. It's a wear item rather than a build fault, but it catches buyers out because a roof that looks fine folded down can be perished at the creases. A full roof replacement is commonly £300-800 depending on spec, more for a heated glass screen.
Two related complaints across the range: judder from a worn or contaminated clutch on earlier cars, and a clutch slave cylinder that fails and lets the pedal go soft or sink to the floor, mostly reported on NC (2005-2015) cars. Nothing has been recalled for either. Judder can sometimes be cured by cleaning up the flywheel and relining; a full clutch kit plus slave cylinder is commonly £200-500 in parts and labour.
A number of ND owners report water getting in around the driver-side hood hinge or bracket where the fabric folds down, sometimes on cars with well under 25,000 miles, showing up as a damp patch of carpet rather than an obvious drip. It hasn't been picked up as an official fault by Mazda and isn't something an MOT tester checks. The usual fix is a reseal or bracket adjustment, not a full roof replacement.
Built from the two sections above.
Same segment (Coupés, convertibles & GT), best MOT record first. Compare before you shortlist.
Head to head with the other popular cars in its class on reliability and common faults.