2003 Ford Mustang — MOT failures & pass rate
292 MOT tests on the 2003 Ford Mustang are in this dataset, and 86.3% of them passed. Coupes & convertibles of a similar age fail 22.6% of the time, so this is 8.9pp better than the group it competes with. Failures cluster in brakes, lighting & signalling and suspension.
What the MOT record shows
Brakes dominates the failure mix at 10.6% of all tests — 3.8 points clear of lighting & signalling, so it is the first thing to check.
At component level the recurring items are rbt (sp), headlamp aim and service brake performance — rbt (sp) alone was recorded 19 times.
Mileage is the strongest signal on the record: 6.3% of 0-30k cars fail, rising to 19.2% once past 90-120k — 3.1× the risk.
Advisories point at the next bill rather than this one: brakes was flagged on 17.5% of tests without failing them.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Brakes | 10.6% | 31 |
| 2 | Lighting & signalling | 6.9% | 20 |
| 3 | Suspension | 2.4% | 7 |
| 4 | Tyres | 1.4% | 4 |
| 5 | Visibility | 1.4% | 4 |
| 6 | Emissions & environmental | 1.4% | 4 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rbt (sp) | 19 |
| 2 | Headlamp aim | 18 |
| 3 | Service brake performance | 14 |
| 4 | Ball joint dust cover | 6 |
| 5 | Catalyst emissions | 4 |
| 6 | Position lamp | 4 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 17.5% | 51 |
| 2 | Emissions & environmental | 15.4% | 45 |
| 3 | Suspension | 14.4% | 42 |
| 4 | Tyres | 12.7% | 37 |
| 5 | Other defects | 8.6% | 25 |
| 6 | Lighting & signalling | 8.2% | 24 |
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 | 48 | 6.3% |
| 30-60k | 83 | 12.0% |
| 60-90k | 79 | 15.2% |
| 90-120k | 52 | 19.2% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 62 | 14.5% |
| 2022 | 65 | 13.9% |
| 2023 | 56 | 10.7% |
| 2024 | 54 | 14.8% |
| 2025 | 55 | 14.5% |
What to check before buying a 2003 Mustang
On a 2003 Mustang, brakes is what the MOT record says goes wrong most — it appeared in 10.6% of tests. Check these areas before you commit.
- Brakes (10.6% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
- Lighting & signalling (6.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (2.4% 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.
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 2003 Ford Mustangs pass their MOT?
86.3% of the 292 2003 Ford Mustang MOT tests in this dataset passed — a 13.7% fail rate.
What is the most common MOT failure on a 2003 Ford Mustang?
Brakes, recorded in 10.6% of tests, followed by lighting & signalling (6.9%).
Does the 2003 Mustang get worse with mileage?
Its MOT fail rate rises from 6.3% in the 0-30k band to 19.2% in the 90-120k band.
Methodology & source. Based on 292 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.