2004 Smart Cabriolet — MOT failures & pass rate
The 2004 Smart Cabriolet passed 74.2% of its 635 recorded MOT tests. That is 1.9 percentage points better than all cars of a similar age, which fail at 27.7%. Failures cluster in lighting & signalling, suspension and emissions & environmental.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 18.3% of tests against 8.8% for the next-worst category.
At component level the recurring items are headlamp aim, catalyst emissions and washers — headlamp aim alone was recorded 67 times.
Condition tracks the odometer closely. Failures run at 21.7% in the 0-30k band and 30.0% in the 90-120k band, a 8.3-point spread.
Brakes is the most common advisory, noted on 29.6% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 27.7% in 2021 to 25.0% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 18.3% | 116 |
| 2 | Suspension | 8.8% | 56 |
| 3 | Emissions & environmental | 8.0% | 51 |
| 4 | Visibility | 7.6% | 48 |
| 5 | Brakes | 6.8% | 43 |
| 6 | Body, structure & corrosion | 4.4% | 28 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 67 |
| 2 | Catalyst emissions | 51 |
| 3 | Washers | 37 |
| 4 | Stop lamp | 36 |
| 5 | Headlamp | 33 |
| 6 | Position lamp | 21 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 29.6% | 188 |
| 2 | Suspension | 25.2% | 160 |
| 3 | Tyres | 22.5% | 143 |
| 4 | Lighting & signalling | 13.4% | 85 |
| 5 | Emissions & environmental | 10.2% | 65 |
| 6 | Body, structure & corrosion | 6.8% | 43 |
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 | 46 | 21.7% |
| 30-60k | 168 | 19.1% |
| 60-90k | 285 | 28.8% |
| 90-120k | 110 | 30.0% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 159 | 27.7% |
| 2022 | 142 | 25.4% |
| 2023 | 135 | 23.7% |
| 2024 | 107 | 27.1% |
| 2025 | 92 | 25.0% |
What to check before buying a 2004 Cabriolet
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 18.3% of tests. Start there.
- Lighting & signalling (18.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (8.8% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Emissions & environmental (8.0% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
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 2004 Smart Cabriolets pass their MOT?
74.2% of the 635 2004 Smart Cabriolet MOT tests in this dataset passed — a 25.8% fail rate.
What is the most common MOT failure on a 2004 Smart Cabriolet?
Lighting & signalling, recorded in 18.3% of tests, followed by suspension (8.8%).
Does the 2004 Cabriolet get worse with mileage?
Its MOT fail rate rises from 21.7% in the 0-30k band to 30.0% in the 90-120k band.
Methodology & source. Based on 635 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.