The picture
420: above-average pass rates, with caveats
Across 659 MOT tests, the 420 returns 83.0% first-time pass — above the UK fleet average. The single most-logged Major fail is a torn suspension dust cover. Windscreen washers not working and the strength or continuity of the load bearing round out the top three. Average tested mileage sits at 101,734, 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
A suspension joint dust cover severely deteriorated
69 occurrences · 10.5% of tests
- 02
Windscreen washers not working or not providing sufficient fluid to clear the windscreen
18 occurrences · 2.7% of tests
- 03
The strength or continuity of the load bearing structure within 30cm of any sub-frame, spring or suspension component mounting (a 'prescribed area') is significantly reduced or inadequately repaired
17 occurrences · 2.6% of tests
- 04
A tyre seriously damaged
15 occurrences · 2.3% of tests
- 05
The aim of a headlamp is not within limits laid down in the requirements
14 occurrences · 2.1% of tests
- 06
Steering rack gaiter or ball joint dust cover damaged or deteriorated
12 occurrences · 1.8% of tests
- 07
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
12 occurrences · 1.8% of tests
- 08
A rear registration plate lamp or light source missing or inoperative in the case of multiple lamps or light sources
12 occurrences · 1.8% of tests
- 09
A suspension joint dust cover missing or no longer prevents the ingress of dirt etc
11 occurrences · 1.7% of tests
- 10
Emissions levels exceed default limits
11 occurrences · 1.7% 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
£90–£320
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.