2003 Mercedes-Benz Cl 500 — MOT failures & pass rate
1,050 MOT tests on the 2003 Mercedes-Benz Cl 500 are in this dataset, and 80.8% of them passed. All cars of a similar age fail 27.6% of the time, so this is 8.4pp better than the group it competes with. Failures cluster in suspension, lighting & signalling and brakes.
What the MOT record shows
No single area dominates — suspension (8.6%) and lighting & signalling (7.3%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are ball joint, tread depth and rigid brake pipes — ball joint alone was recorded 53 times.
Mileage matters less than usual here: the 2003 Cl 500 fails 19.8% of the time in the 30-60k band and 18.9% at 150k+, a spread of only 0.9 points.
Brakes is the most common advisory, noted on 29.0% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 20.3% in 2021 to 16.3% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 8.6% | 90 |
| 2 | Lighting & signalling | 7.3% | 77 |
| 3 | Brakes | 6.4% | 67 |
| 4 | Tyres | 5.1% | 54 |
| 5 | Visibility | 3.0% | 32 |
| 6 | Seat belts & restraints | 2.9% | 31 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Ball joint | 53 |
| 2 | Tread depth | 34 |
| 3 | Rigid brake pipes | 31 |
| 4 | Headlamp aim | 30 |
| 5 | SRS malfunction indicator lamp | 28 |
| 6 | Shock absorbers | 27 |
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 | 29.0% | 305 |
| 2 | Suspension | 26.6% | 279 |
| 3 | Tyres | 25.1% | 263 |
| 4 | Body, structure & corrosion | 8.8% | 92 |
| 5 | Lighting & signalling | 8.4% | 88 |
| 6 | Emissions & environmental | 8.0% | 84 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 96 | 19.8% |
| 60-90k | 290 | 14.8% |
| 90-120k | 339 | 22.1% |
| 120-150k | 181 | 17.7% |
| 150k+ | 111 | 18.9% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 261 | 20.3% |
| 2022 | 232 | 19.8% |
| 2023 | 208 | 20.7% |
| 2024 | 183 | 18.0% |
| 2025 | 166 | 16.3% |
What to check before buying a 2003 Cl 500
The failure pattern for this year is specific enough to inspect against: suspension accounted for 8.6% of tests. Start there.
- Suspension (8.6% 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.
- Lighting & signalling (7.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (6.4% 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 2003 Mercedes-Benz Cl 500s pass their MOT?
80.8% of the 1,050 2003 Mercedes-Benz Cl 500 MOT tests in this dataset passed — a 19.2% fail rate.
What is the most common MOT failure on a 2003 Mercedes-Benz Cl 500?
Suspension, recorded in 8.6% of tests, followed by lighting & signalling (7.3%).
Does the 2003 Cl 500 get worse with mileage?
Its MOT fail rate rises from 19.8% in the 30-60k band to 18.9% in the 150k+ band.
Methodology & source. Based on 1,050 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.