The picture
420: a strong MOT record by UK norms
Across 71,832 MOT tests, the 420 returns 85.6% first-time pass — comfortably ahead of the UK fleet average. The single most-logged Major fail is tyre tread under the limit. A tyre with the cords showing and a seriously damaged tyre round out the top three. Average tested mileage sits at 58,580, 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
1,920 occurrences · 2.7% of tests
- 02
A tyre cords visible or damaged
1,660 occurrences · 2.3% of tests
- 03
A tyre seriously damaged
1,469 occurrences · 2.0% of tests
- 04
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
1,422 occurrences · 2.0% of tests
- 05
A tyre seriously damaged
1,256 occurrences · 1.7% of tests
- 06
a brake lining or pad worn below 1.5mm
980 occurrences · 1.4% of tests
- 07
Windscreen washers not working or not providing sufficient fluid to clear the windscreen
581 occurrences · 0.8% of tests
- 08
A shock absorber damaged to the extent that it does not function or showing signs of severe leakage
521 occurrences · 0.7% of tests
- 09
Wiper blade defective
459 occurrences · 0.6% of tests
- 10
A wheel with a loose or missing wheel nut, bolt or stud
393 occurrences · 0.5% 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 2 failures
£120–£190
If every one of this 420'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 420?
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 420 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.