Mazda MX-5 2003: reliability & common MOT faults
Elevated MOT failure patterns for the 2003 Mazda MX-5 include Prescribed areas (rear) (~9.8× peers) and Component mounting prescribed areas (front) (~5.7× peers). Based on UK DVSA open data for test year 2025 (1,244 failed first-attempt tests), compared with similar age and mileage peers. Available test years: 2024, 2025.
Common faults
These are MOT failure patterns that show up more often on this registration year than on similar cars of the same class, age band, and mileage in the same test year (leave-one-out peer comparison; whole model family excluded).
Statistical patterns from MOT defect codes — not manufacturer TSBs, recalls, or a diagnosis of any individual car. Fail and advisory patterns are kept separate.
Based on 1,244 failed first-attempt tests in test year 2025.
Prescribed areas (rear)
This failure pattern appears about 9.8× more often than on similar peer cars — recorded on 100 failed first-attempt tests; 8.0% of failed tests for this model year.
Rear · 100 failures · ×9.8 vs similar cars · 8.0% of failed first tests · Strong pattern — appears far more often than similar cars
Component mounting prescribed areas (front)
This failure pattern appears about 5.7× more often than on similar peer cars — recorded on 110 failed first-attempt tests; 8.8% of failed tests for this model year.
Front · 110 failures · ×5.7 vs similar cars · 8.8% of failed first tests · Strong pattern — appears far more often than similar cars
| # | Fault pattern | Location | Failures | vs similar cars | Share of fails | Confidence |
|---|---|---|---|---|---|---|
| 1 |
Prescribed areas (rear)
Seat belts and supplementary restraint systems > Seat belts > Prescribed areas
|
Rear | 100 | ×9.8 | 8.0% | Strong pattern — appears far more often than similar cars |
| 2 |
Chassis condition (front)
Body, chassis, structure > Chassis > Chassis condition
|
Front | 69 | ×5.8 | 5.5% | Likely common fault pattern |
| 3 |
Component mounting prescribed areas (front)
Suspension > Component mounting prescribed areas
|
Front | 110 | ×5.7 | 8.8% | Strong pattern — appears far more often than similar cars |
| 4 |
Integral vehicle structure condition (rear)
Body, chassis, structure > Integral vehicle structure > Integral vehicle structure condition
|
Rear | 59 | ×4.6 | 4.7% | Likely common fault pattern |
| 5 |
Integral vehicle structure condition (front)
Body, chassis, structure > Integral vehicle structure > Integral vehicle structure condition
|
Front | 37 | ×3.9 | 3.0% | Likely common fault pattern |
| 6 |
Prescribed areas
Seat belts and supplementary restraint systems > Seat belts > Prescribed areas
|
Any | 31 | ×3.9 | 2.5% | Likely common fault pattern |
| 7 |
Chassis condition (rear)
Body, chassis, structure > Chassis > Chassis condition
|
Rear | 66 | ×3.5 | 5.3% | Likely common fault pattern |
| 8 |
Coil spring (rear)
Suspension > Springs > Coil springs > Coil spring
|
Rear | 98 | ×3.5 | 7.9% | Likely common fault pattern |
| 9 |
Parking brake performance (rear)
Brakes > Brake performance > Parking brake performance > Rbt > Parking brake performance
|
Rear | 32 | ×2.8 | 2.6% | Possible elevated fault |
| 10 |
Service brake performance (front)
Brakes > Brake performance > Service brake performance > Rbt > Service brake performance
|
Front | 76 | ×2.8 | 6.1% | Possible elevated fault |
Only patterns that clear minimum sample and elevation thresholds are shown (at least 20 failures and 2.0× peer lift).
Wear patterns
These patterns look like wear or usage effects rather than model-specific design faults. Tyres, brake friction material, and alignment-related defects often track mileage and road use. They are not treated as a model design fault in our common-faults ranking.
| # | Pattern | Location | Failures | vs similar cars | Share of fails | Confidence |
|---|---|---|---|---|---|---|
| 1 |
Brake pads (rear)
Brakes > Mechanical brake components > Brake linings and pads > Brake pads
|
Rear | 45 | ×2.6 | 3.6% | Wear / usage pattern — not treated as a model design fault |
Advisories
Advisory items recorded on failed first-attempt tests that appear elevated versus peers. Advisories are not a fail rate — they flag issues noted at the test, often before they become failures.
| # | Advisory pattern | Location | Notes | vs similar cars | Share | Confidence |
|---|---|---|---|---|---|---|
| 1 |
Suspension arm
Suspension > Suspension arms > Suspension arm
|
Any | 46 | ×11.0 | 3.7% | Elevated vs peers |
| 2 |
Prescribed areas (rear)
Seat belts and supplementary restraint systems > Seat belts > Prescribed areas
|
Rear | 37 | ×10.8 | 3.0% | Strong pattern — appears far more often than similar cars |
| 3 |
Prescribed areas
Seat belts and supplementary restraint systems > Seat belts > Prescribed areas
|
Any | 21 | ×7.7 | 1.7% | Likely common fault pattern |
| 4 |
Chassis condition (front)
Body, chassis, structure > Chassis > Chassis condition
|
Front | 49 | ×5.8 | 3.9% | Likely common fault pattern |
| 5 |
Suspension arm (rear)
Suspension > Suspension arms > Suspension arm
|
Rear | 143 | ×5.4 | 11.5% | Elevated vs peers |
| 6 |
Component mounting prescribed areas (front)
Suspension > Component mounting prescribed areas
|
Front | 57 | ×4.8 | 4.6% | Strong pattern — appears far more often than similar cars |
| 7 |
Suspension arm (front)
Suspension > Suspension arms > Suspension arm
|
Front | 120 | ×3.9 | 9.6% | Elevated vs peers |
| 8 |
Linkage ball joints (rear)
Suspension > Anti-roll bars > Linkage ball joints
|
Rear | 21 | ×3.9 | 1.7% | Elevated vs peers |
FAQs
About this data
Universe. UK class 4 cars only; normal MOT tests (not retests); results pass, PRS, or fail; one first test per vehicle per calendar year.
PRS policy. PRS means the vehicle failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.
Peer baseline. We compare this model year with other class 4 cars of similar age and mileage in the same test year, excluding the whole model family so the car is not compared with itself (leave-one-out peer baseline).
Data years. Test years covered: 2024, 2025.
Limitations.
- MOT tests do not cover engine internals, gearboxes, or many electronic modules — so this is not a full reliability score.
- Common faults are inferred from MOT defect statistics, not manufacturer TSBs or recalls.
- Matching on age and mileage reduces but does not remove every usage or maintenance difference between cars.
- Pass rates and star scores appear only when those data marts are available; this page never invents them.
Display rules config: 1
Contains public sector information licensed under the Open Government Licence v3.0.