2003 Mercedes-Benz SLK MOT pass rate, common failures & what to check
In 2025, 67.9% of Mercedes-Benz SLKs first used in 2003 passed their MOT first time, against 58.7% for all cars first used in 2003. Across 5,114 SLK first tests from 2023 to 2025, the most common failure areas were lamps and electrical equipment, brakes and suspension.
This page analyses first MOT tests for Mercedes-Benz SLKs first used in 2003 (all trims grouped): 2021 to 2025 for the pass-rate trend, and 2023 to 2025 for the failure and advisory analysis — plus what is worth checking before you buy one.
Data: DVSA anonymised MOT tests to December 2025 · Calculated by SortedCars · Updated October 2026
How the 2003 Mercedes-Benz SLK MOT pass rate has changed
Share of first tests passed in each year, SLKs first used in 2003 against all cars first used in 2003 (any make or fuel; not adjusted for mileage, fuel or use). In 2025 the SLK figure was 9.2 points higher.
View this chart as a table
| Test year | 2003 SLK | All cars first used 2003 | SLK first tests |
|---|---|---|---|
| 2021 | 65.5% | 54.0% | 2,236 |
| 2022 | 67.9% | 55.7% | 2,072 |
| 2023 | 65.1% | 56.7% | 1,894 |
| 2024 | 65.7% | 57.2% | 1,701 |
| 2025 | 67.9% | 58.7% | 1,519 |
Common 2003 Mercedes-Benz SLK MOT failures
Share of the 1,732 failed first tests (2023–2025) with at least one failure in each area. A test can fail in more than one area, so the shares add up to more than 100%.
Most common failure items
| DVSA failure item | Share of failed first tests | Tests |
|---|---|---|
| Stop lamp: not working | 19.8% | 343 |
| Coil spring: fractured or broken | 14.7% | 255 |
| Position lamp: not working | 12.1% | 209 |
| Headlamp aim: projected beam image is obviously incorrect | 8.5% | 148 |
| Malfunction indicator lamp: inoperative or indicates a malfunction | 8.2% | 142 |
Item names are DVSA’s own wording. 2023–2025 combined.
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Typical repair costs for common MOT failures
Typical UK garage prices for the job, not for an SLK in particular, and not a quote.
| Failure item | Typical job | Typical UK price | Usual range |
|---|---|---|---|
| Coil spring: fractured or broken | Coil spring replacement | £248 | £175–£400 |
From published UK repair-cost guides, checked September 2026. Only jobs with a published typical price are shown.
What to check on a 2003 Mercedes-Benz SLK before buying
The three areas where failed first tests most often had a fault, 2023–2025.
- Lamps and electrics. Ask someone to watch while you work the brake lights, indicators, sidelights, dipped and main beam, and the number-plate lamps.
- Brakes. Worth looking at the discs and pads through the wheel spokes for scoring and a worn lip, and noticing on the test drive whether the car pulls to one side or the pedal feels long.
- Suspension. Worth looking behind the front wheels with a torch at the coil springs, and listening for knocks over bumps on the test drive.
Common 2003 Mercedes-Benz SLK MOT advisories
Advisories are points the tester noted that did not fail the car. Most common on 2003 SLKs, as a share of all 5,114 first tests, 2023–2025.
| DVSA advisory item | Share of first tests | Tests |
|---|---|---|
| Rigid brake pipes: corroded, covered in grease or other material | 17.1% | 876 |
| Tread depth: worn close to legal limit/worn on edge | 13.5% | 689 |
| Tyre condition: slightly damaged/cracking or perishing | 10.1% | 514 |
| Engine oil leaks: leak, but not excessive | 9.9% | 506 |
| Wheel bearings: has slight play | 8.5% | 435 |
Questions about the 2003 Mercedes-Benz SLK MOT
What is the MOT pass rate of a 2003 Mercedes-Benz SLK?
In 2025, 67.9% of SLKs first used in 2003 passed their MOT first time, against 58.7% for all cars first used in 2003. A car fixed during the test counts as a fail.
What does a 2003 SLK most often fail its MOT on?
Lamps and electrical equipment (in 56.7% of failed first tests, 2023–2025), brakes (26.6%) and suspension (24.9%). The single most common item was “Stop lamp: not working” (19.8%).
How often does a 2003 Mercedes-Benz SLK fail its MOT?
In 2025, 32.1% of first tests on SLKs first used in 2003 did not pass first time: 25.5% failed, and a further 6.6% had a fault fixed during the test (counted as a fail here). Across 2023–2025, 1,732 of 5,114 first tests did not pass first time.
What are the most common 2003 Mercedes-Benz SLK MOT advisories?
“Rigid brake pipes: corroded, covered in grease or other material” (on 17.1% of first tests, 2023–2025), “Tread depth: worn close to legal limit/worn on edge” (13.5%), “Tyre condition: slightly damaged/cracking or perishing” (10.1%), “Engine oil leaks: leak, but not excessive” (9.9%) and “Wheel bearings: has slight play” (8.5%).
Is a 2003 Mercedes-Benz SLK reliable?
An MOT pass rate shows what failed at the test, not how reliable a car is. For this group of cars the first-time pass rate went from 65.5% in 2021 to 67.9% in 2025. For one particular car, its own MOT history matters more than the average.
Other cars first used in 2003
The most-tested cars from the same year. Each page uses the same method.
2003 Volkswagen Golf MOT statistics · 2003 Ford Fiesta MOT statistics · 2003 MINI Hatch MOT statistics · 2003 Ford Focus MOT statistics · 2003 Toyota Yaris MOT statistics
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