The picture
Interstar: a below-average pass rate worth digging into
Across 1,299 MOT tests, the Interstar returns 63.0% first-time pass — well below the UK fleet average. The single most-logged Major fail is a number-plate lamp out. Windscreen damage and a split CV-joint boot round out the top three. Average tested mileage sits at 139,000, 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 rear registration plate lamp or light source missing or inoperative in the case of multiple lamps or light sources
119 occurrences · 9.2% of tests
- 02
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
117 occurrences · 9.0% of tests
- 03
A transmission shaft constant velocity joint boot severely deteriorated
114 occurrences · 8.8% of tests
- 04
Parking brake efficiency below minimum requirement
113 occurrences · 8.7% of tests
- 05
Steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc
78 occurrences · 6.0% of tests
- 06
Steering rack gaiter or ball joint dust cover damaged or deteriorated
69 occurrences · 5.3% of tests
- 07
A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc
64 occurrences · 4.9% of tests
- 08
A suspension pin, bush or joint excessively worn
61 occurrences · 4.7% of tests
- 09
Parking brake inoperative on one side
60 occurrences · 4.6% of tests
- 10
Parking brake efficiency less than 50% of the required value
59 occurrences · 4.5% 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
£88–£275
If every one of this Interstar'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 Interstar?
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 Interstar 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.