2020 Mercedes-Benz Amg A 45 S 4Matic+ — MOT failures & pass rate
1,920 MOT tests on the 2020 Mercedes-Benz Amg A 45 S 4Matic+ are in this dataset, and 89.3% of them passed. That is 1.5 percentage points worse than all cars of a similar age, which fail at 9.3%. Failures cluster in tyres, emissions & environmental and visibility.
What the MOT record shows
One area stands out: tyres, recorded in 8.1% of tests against 1.6% for the next-worst category.
At component level the recurring items are catalyst emissions, tread depth and wipers — catalyst emissions alone was recorded 34 times.
Mileage matters less than usual here: the 2020 Amg A 45 S 4Matic+ fails 10.0% of the time in the 0-30k band and 6.7% at 60-90k, a spread of only 3.4 points.
Tyres is the most common advisory, noted on 16.9% of tests — work that passed today but is likely due soon.
The trend is worsening — 6.8% of tests failed in 2022 against 10.0% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 8.1% | 156 |
| 2 | Emissions & environmental | 1.6% | 30 |
| 3 | Visibility | 0.8% | 16 |
| 4 | Suspension | 0.6% | 11 |
| 5 | Lighting & signalling | 0.5% | 10 |
| 6 | Brakes | 0.5% | 10 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Catalyst emissions | 34 |
| 2 | Tread depth | 18 |
| 3 | Wipers | 12 |
| 4 | Headlamp aim | 11 |
| 5 | Registration plates | 10 |
| 6 | Washers | 6 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 16.9% | 324 |
| 2 | Brakes | 6.6% | 127 |
| 3 | Other defects | 3.7% | 71 |
| 4 | Visibility | 2.9% | 55 |
| 5 | Road wheels | 1.1% | 22 |
| 6 | Suspension | 1.0% | 19 |
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 | 1,178 | 10.0% |
| 30-60k | 680 | 12.2% |
| 60-90k | 60 | 6.7% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2022 | 44 | 6.8% |
| 2023 | 649 | 11.7% |
| 2024 | 614 | 10.8% |
| 2025 | 613 | 10.0% |
What to check before buying a 2020 Amg A 45 S 4Matic+
The failure pattern for this year is specific enough to inspect against: tyres accounted for 8.1% of tests. Start there.
- Tyres (8.1% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Emissions & environmental (1.6% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Visibility (0.8% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
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 2020 Mercedes-Benz Amg A 45 S 4Matic+s pass their MOT?
89.3% of the 1,920 2020 Mercedes-Benz Amg A 45 S 4Matic+ MOT tests in this dataset passed — a 10.7% fail rate.
What is the most common MOT failure on a 2020 Mercedes-Benz Amg A 45 S 4Matic+?
Tyres, recorded in 8.1% of tests, followed by emissions & environmental (1.6%).
Does the 2020 Amg A 45 S 4Matic+ get worse with mileage?
Its MOT fail rate rises from 10.0% in the 0-30k band to 6.7% in the 60-90k band.
Methodology & source. Based on 1,920 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.