2014 SEAT Mii — MOT failures & pass rate
The 2014 SEAT Mii passed 86.4% of its 17,851 recorded MOT tests. Against all cars of a similar age (18.4% fail rate), the 2014 Mii comes out 4.7pp better. Failures cluster in lighting & signalling, brakes and visibility.
What the MOT record shows
No single area dominates — lighting & signalling (6.0%) and brakes (5.0%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are service brake performance, catalyst emissions and headlamp aim — service brake performance alone was recorded 609 times.
Mileage is the strongest signal on the record: 7.1% of 0-30k cars fail, rising to 30.4% once past 150k — 4.3× the risk.
Advisories point at the next bill rather than this one: tyres was flagged on 24.4% of tests without failing them.
The trend is worsening — 10.9% of tests failed in 2021 against 16.2% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 6.0% | 1,070 |
| 2 | Brakes | 5.0% | 899 |
| 3 | Visibility | 3.4% | 614 |
| 4 | Tyres | 3.3% | 589 |
| 5 | Suspension | 2.4% | 424 |
| 6 | Body, structure & corrosion | 2.1% | 376 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Service brake performance | 609 |
| 2 | Catalyst emissions | 542 |
| 3 | Headlamp aim | 532 |
| 4 | Wipers | 445 |
| 5 | Tread depth | 402 |
| 6 | Registration plate lamp(s) | 287 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 24.4% | 4,359 |
| 2 | Brakes | 18.1% | 3,226 |
| 3 | Suspension | 8.1% | 1,437 |
| 4 | Other defects | 7.0% | 1,246 |
| 5 | Visibility | 2.9% | 509 |
| 6 | Body, structure & corrosion | 2.0% | 349 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 2,875 | 7.1% |
| 30-60k | 8,814 | 11.9% |
| 60-90k | 4,693 | 18.0% |
| 90-120k | 1,219 | 23.1% |
| 120-150k | 204 | 23.5% |
| 150k+ | 46 | 30.4% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,467 | 10.9% |
| 2022 | 3,500 | 10.9% |
| 2023 | 3,572 | 13.6% |
| 2024 | 3,689 | 16.4% |
| 2025 | 3,623 | 16.2% |
What to check before buying a 2014 Mii
On a 2014 Mii, lighting & signalling is what the MOT record says goes wrong most — it appeared in 6.0% of tests. Check these areas before you commit.
- Lighting & signalling (6.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (5.0% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
- Visibility (3.4% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 2014 SEAT Miis pass their MOT?
86.4% of the 17,851 2014 SEAT Mii MOT tests in this dataset passed — a 13.7% fail rate.
What is the most common MOT failure on a 2014 SEAT Mii?
Lighting & signalling, recorded in 6.0% of tests, followed by brakes (5.0%).
Does the 2014 Mii get worse with mileage?
Its MOT fail rate rises from 7.1% in the 0-30k band to 30.4% in the 150k+ band.
Methodology & source. Based on 17,851 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.