2021 Audi Q4 E-Tron S Line 35 — MOT failures & pass rate
Across 1,063 MOT tests analysed for the 2021 Audi Q4 E-Tron S Line 35, the most common recorded failure areas were tyres, visibility and lighting & signalling. Its pass rate of 89.6% was below the average for cars of a similar age (91.2%).
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 9.0% | 96 |
| 2 | Visibility | 1.7% | 18 |
| 3 | Lighting & signalling | 1.1% | 12 |
| 4 | Seat belts & restraints | 0.8% | 8 |
| 5 | Other defects | 0.4% | 4 |
| 6 | Brakes | 0.3% | 3 |
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 | 44 |
| 2 | Headlamp aim | 16 |
| 3 | Washers | 12 |
| 4 | Registration plates | 5 |
| 5 | SRS malfunction indicator lamp | 5 |
| 6 | Wipers | 5 |
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 | 23.4% | 249 |
| 2 | Other defects | 6.3% | 67 |
| 3 | Suspension | 2.4% | 25 |
| 4 | Brakes | 2.1% | 22 |
| 5 | Visibility | 1.9% | 20 |
| 6 | Lighting & signalling | 0.6% | 6 |
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 | 542 | 9.0% |
| 30-60k | 467 | 12.2% |
| 60-90k | 50 | 8.0% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2024 | 538 | 11.9% |
| 2025 | 524 | 9.0% |
What to check before buying a 2021 Q4 E-Tron S Line 35
Before buying a 2021 Audi Q4 E-Tron S Line 35, focus on the areas it most often fails on. Tyres accounted for 9.0% of tests for this year.
- Tyres (9.0% 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 (1.7% 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 (1.1% 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 Q4 E-Tron S Line 35s pass their MOT?
89.6% of the 1,063 2021 Audi Q4 E-Tron S Line 35 MOT tests in this dataset passed — a 10.4% fail rate.
What is the most common MOT failure on a 2021 Audi Q4 E-Tron S Line 35?
Tyres, recorded in 9.0% of tests, followed by visibility (1.7%).
Does the 2021 Q4 E-Tron S Line 35 get worse with mileage?
Its MOT fail rate rises from 9.0% in the 0-30k band to 8.0% in the 60-90k band.
Methodology & source. Based on 1,063 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.