The picture
520: middle-of-the-pack on first-time pass
Across 97,218 MOT tests, the 520 returns 79.5% first-time pass — roughly in line with the UK fleet average. The single most-logged Major fail is tyre tread under the limit. Windscreen damage and a broken or weak spring round out the top three. Average tested mileage sits at 113,789, which is the lens to read those failure rankings through. If you own one and the next test is close, the ranked list below is a sensible pre-test checklist.
Top ten reasons for rejection.
- 01
Tyre tread depth not in accordance with the requirements
3,480 occurrences · 3.6% of tests
- 02
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
3,356 occurrences · 3.5% of tests
- 03
A spring or spring component fractured or seriously weakened
2,867 occurrences · 2.9% of tests
- 04
A tyre cords visible or damaged
2,011 occurrences · 2.1% of tests
- 05
A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning
1,531 occurrences · 1.6% of tests
- 06
Wiper blade missing or obviously not clearing the windscreen
1,273 occurrences · 1.3% of tests
- 07
a brake lining or pad worn below 1.5mm
1,224 occurrences · 1.3% of tests
- 08
A tyre seriously damaged
1,218 occurrences · 1.3% of tests
- 09
A suspension pin, bush or joint excessively worn
1,217 occurrences · 1.3% of tests
- 10
Headlamp reflector or lens slightly defective
1,037 occurrences · 1.1% of tests
Counts cover Major and Dangerous defects logged at test. Advisory items excluded so this shows why a car was rejected, not just what the tester flagged in passing.
Worst-case fix budget · top 3 failures
£200–£430
If every one of this 520's most-logged Major fails hit at the same MOT, that's the real-world UK garage range. Reality is usually one or two items, not all of them. Open the estimator →
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Tools that pre-empt a retest.
Picked against this car's top failure patterns. Affiliate links to Amazon UK — we earn a small cut at no cost to you. Disclosed up-front, doesn't shape the data.
Buying or keeping a 520?
Use the failure ranking as a pre-test checklist or a haggling lever. Treat the headline pass rate as a fleet-wide trend, not a guarantee on any individual car.
If you own a 520 and your last MOT looked nothing like the ranked failures above, that's normal — individual cars vary widely. The ranking shows the patterns testers flag most often across the country.