2005 Audi S4 — MOT failures & pass rate
787 MOT tests on the 2005 Audi S4 are in this dataset, and 83.5% of them passed. That is 7.6 percentage points better than executive cars of a similar age, which fail at 24.1%. Failures cluster in lighting & signalling, suspension and tyres.
What the MOT record shows
No single area dominates — lighting & signalling (7.2%) and suspension (7.2%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are pins and bushes, headlamp aim and ball joint dust cover — pins and bushes alone was recorded 41 times.
Mileage matters less than usual here: the 2005 S4 fails 14.9% of the time in the 30-60k band and 13.4% at 150k+, a spread of only 1.5 points.
Advisories point at the next bill rather than this one: suspension was flagged on 27.6% of tests without failing them.
The trend is improving — the fail rate fell from 17.4% in 2021 to 14.6% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 7.2% | 57 |
| 2 | Suspension | 7.2% | 57 |
| 3 | Tyres | 4.3% | 34 |
| 4 | Emissions & environmental | 3.8% | 30 |
| 5 | Brakes | 3.7% | 29 |
| 6 | Body, structure & corrosion | 3.2% | 25 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Pins and bushes | 41 |
| 2 | Headlamp aim | 28 |
| 3 | Ball joint dust cover | 22 |
| 4 | Catalyst emissions | 20 |
| 5 | Headlamp | 20 |
| 6 | Ball joint | 18 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 27.6% | 217 |
| 2 | Emissions & environmental | 23.4% | 184 |
| 3 | Tyres | 18.3% | 144 |
| 4 | Brakes | 17.9% | 141 |
| 5 | Lighting & signalling | 11.7% | 92 |
| 6 | Body, structure & corrosion | 9.8% | 77 |
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 | 47 | 14.9% |
| 60-90k | 228 | 16.2% |
| 90-120k | 258 | 20.2% |
| 120-150k | 154 | 13.0% |
| 150k+ | 97 | 13.4% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 184 | 17.4% |
| 2022 | 176 | 15.9% |
| 2023 | 148 | 14.9% |
| 2024 | 142 | 19.7% |
| 2025 | 137 | 14.6% |
What to check before buying a 2005 S4
On a 2005 S4, lighting & signalling is what the MOT record says goes wrong most — it appeared in 7.2% of tests. Check these areas before you commit.
- Lighting & signalling (7.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (7.2% 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.
- Tyres (4.3% 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.
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 2005 Audi S4s pass their MOT?
83.5% of the 787 2005 Audi S4 MOT tests in this dataset passed — a 16.5% fail rate.
What is the most common MOT failure on a 2005 Audi S4?
Lighting & signalling, recorded in 7.2% of tests, followed by suspension (7.2%).
Does the 2005 S4 get worse with mileage?
Its MOT fail rate rises from 14.9% in the 30-60k band to 13.4% in the 150k+ band.
Methodology & source. Based on 787 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.