2021 Audi A3 S Line 35 — MOT failures & pass rate
Across 3,570 MOT tests analysed for the 2021 Audi A3 S Line 35, the most common recorded failure areas were tyres, visibility and lighting & signalling. Its pass rate of 92.1% was in line with the average for cars of a similar age (91.2%). Higher-mileage examples failed more often — 15.0% in the 60-90k group versus 6.9% in the 0-30k group.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 6.6% | 235 |
| 2 | Visibility | 1.1% | 38 |
| 3 | Lighting & signalling | 0.8% | 27 |
| 4 | Suspension | 0.7% | 26 |
| 5 | Brakes | 0.4% | 14 |
| 6 | Seat belts & restraints | 0.3% | 10 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Tread depth | 115 |
| 2 | Headlamp aim | 33 |
| 3 | Washers | 26 |
| 4 | Shock absorbers | 20 |
| 5 | Wipers | 17 |
| 6 | Brake pads | 17 |
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 | 24.3% | 866 |
| 2 | Brakes | 6.4% | 227 |
| 3 | Other defects | 6.1% | 219 |
| 4 | Suspension | 3.1% | 111 |
| 5 | Visibility | 2.5% | 88 |
| 6 | Road wheels | 0.4% | 15 |
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 | 2,155 | 6.9% |
| 30-60k | 1,303 | 8.9% |
| 60-90k | 100 | 15.0% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 3,536 | 7.9% |
| Diesel | 34 | 5.9% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 74 | 4.0% |
| 2024 | 1,747 | 8.1% |
| 2025 | 1,749 | 7.8% |
What to check before buying a 2021 A3 S Line 35
Before buying a 2021 Audi A3 S Line 35, focus on the areas it most often fails on. Tyres accounted for 6.6% of tests for this year.
- Tyres (6.6% 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.
- Visibility (1.1% 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.
- Lighting & signalling (0.8% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£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 2021 Audi A3 S Line 35s pass their MOT?
92.1% of the 3,570 2021 Audi A3 S Line 35 MOT tests in this dataset passed — a 7.9% fail rate.
What is the most common MOT failure on a 2021 Audi A3 S Line 35?
Tyres, recorded in 6.6% of tests, followed by visibility (1.1%).
Does the 2021 A3 S Line 35 get worse with mileage?
Its MOT fail rate rises from 6.9% in the 0-30k band to 15.0% in the 60-90k band.
Methodology & source. Based on 3,570 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.