2004 Smart (Mcc) Forfour — MOT failures & pass rate
Across 1,746 MOT tests analysed for the 2004 Smart (Mcc) Forfour, the most common recorded failure areas were lighting & signalling, suspension and brakes. Its pass rate of 71.1% was below the average for cars of a similar age (74.2%). Higher-mileage examples failed more often — 36.3% in the 150k+ group versus 25.0% in the 0-30k group.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 20.7% | 362 |
| 2 | Suspension | 9.4% | 164 |
| 3 | Brakes | 9.2% | 161 |
| 4 | Body, structure & corrosion | 7.7% | 135 |
| 5 | Visibility | 5.7% | 100 |
| 6 | Tyres | 5.5% | 96 |
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 | 207 |
| 2 | Headlamp | 173 |
| 3 | Wipers | 89 |
| 4 | Track rod end | 81 |
| 5 | Position lamp | 79 |
| 6 | Stop lamp | 71 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 37.5% | 655 |
| 2 | Brakes | 28.9% | 504 |
| 3 | Lighting & signalling | 27.2% | 474 |
| 4 | Tyres | 27.1% | 473 |
| 5 | Other defects | 13.9% | 242 |
| 6 | Body, structure & corrosion | 10.0% | 175 |
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 | 36 | 25.0% |
| 30-60k | 176 | 22.2% |
| 60-90k | 460 | 26.3% |
| 90-120k | 532 | 29.5% |
| 120-150k | 341 | 30.8% |
| 150k+ | 190 | 36.3% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 1,413 | 28.0% |
| Diesel | 333 | 32.7% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 517 | 27.9% |
| 2022 | 419 | 30.6% |
| 2023 | 331 | 27.2% |
| 2024 | 267 | 31.1% |
| 2025 | 212 | 28.3% |
What to check before buying a 2004 Forfour
Before buying a 2004 Smart (Mcc) Forfour, focus on the areas it most often fails on. Lighting & signalling accounted for 20.7% of tests for this year.
- Lighting & signalling (20.7% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (9.4% 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.
- Brakes (9.2% 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.
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 (Mcc) Forfours pass their MOT?
71.1% of the 1,746 2004 Smart (Mcc) Forfour MOT tests in this dataset passed — a 28.9% fail rate.
What is the most common MOT failure on a 2004 Smart (Mcc) Forfour?
Lighting & signalling, recorded in 20.7% of tests, followed by suspension (9.4%).
Does the 2004 Forfour get worse with mileage?
Its MOT fail rate rises from 25.0% in the 0-30k band to 36.3% in the 150k+ band.
Methodology & source. Based on 1,746 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.