2006 Mercedes-Benz Cl 500 — MOT failures & pass rate
301 MOT tests on the 2006 Mercedes-Benz Cl 500 are in this dataset, and 80.7% of them passed. Against all cars of a similar age (27.3% fail rate), the 2006 Cl 500 comes out 8.1pp better. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (8.0%) and suspension (7.6%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are rigid brake pipes, shock absorbers and headlamp aim — rigid brake pipes alone was recorded 15 times.
Mileage is the strongest signal on the record: 15.9% of 30-60k cars fail, rising to 22.4% once past 120-150k.
Advisories point at the next bill rather than this one: brakes was flagged on 24.3% of tests without failing them.
The trend is improving — the fail rate fell from 27.4% in 2021 to 15.7% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 8.0% | 24 |
| 2 | Suspension | 7.6% | 23 |
| 3 | Brakes | 7.3% | 22 |
| 4 | Visibility | 4.0% | 12 |
| 5 | Tyres | 3.3% | 10 |
| 6 | Emissions & environmental | 1.7% | 5 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rigid brake pipes | 15 |
| 2 | Shock absorbers | 11 |
| 3 | Headlamp aim | 9 |
| 4 | Ball joint | 9 |
| 5 | Service brake performance | 8 |
| 6 | Tread depth | 7 |
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 | 24.3% | 73 |
| 2 | Tyres | 21.9% | 66 |
| 3 | Suspension | 21.3% | 64 |
| 4 | Lighting & signalling | 11.3% | 34 |
| 5 | Emissions & environmental | 8.6% | 26 |
| 6 | Body, structure & corrosion | 7.0% | 21 |
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 | 44 | 15.9% |
| 60-90k | 79 | 15.2% |
| 90-120k | 101 | 17.8% |
| 120-150k | 49 | 22.4% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 73 | 27.4% |
| 2022 | 62 | 17.7% |
| 2023 | 61 | 16.4% |
| 2024 | 54 | 16.7% |
| 2025 | 51 | 15.7% |
What to check before buying a 2006 Cl 500
On a 2006 Cl 500, lighting & signalling is what the MOT record says goes wrong most — it appeared in 8.0% of tests. Check these areas before you commit.
- Lighting & signalling (8.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (7.6% 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.
- Brakes (7.3% 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 2006 Mercedes-Benz Cl 500s pass their MOT?
80.7% of the 301 2006 Mercedes-Benz Cl 500 MOT tests in this dataset passed — a 19.3% fail rate.
What is the most common MOT failure on a 2006 Mercedes-Benz Cl 500?
Lighting & signalling, recorded in 8.0% of tests, followed by suspension (7.6%).
Does the 2006 Cl 500 get worse with mileage?
Its MOT fail rate rises from 15.9% in the 30-60k band to 22.4% in the 120-150k band.
Methodology & source. Based on 301 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.