The picture
300: a below-average pass rate worth digging into
Across 4,841 MOT tests, the 300 returns 70.0% first-time pass — well below the UK fleet average. The single most-logged Major fail is worn suspension bushes. A torn suspension dust cover and parking brake efficiency less than 50% of the round out the top three. Average tested mileage sits at 111,635, 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 pin, bush or joint excessively worn
348 occurrences · 7.2% of tests
- 02
A suspension joint dust cover severely deteriorated
272 occurrences · 5.6% of tests
- 03
Parking brake efficiency less than 50% of the required value
269 occurrences · 5.6% of tests
- 04
Parking brake efficiency below minimum requirement
268 occurrences · 5.5% of tests
- 05
A rear registration plate lamp or light source missing or inoperative in the case of multiple lamps or light sources
267 occurrences · 5.5% of tests
- 06
A steering ball joint with excessive wear or free play
230 occurrences · 4.8% of tests
- 07
Parking brake inoperative on one side
182 occurrences · 3.8% of tests
- 08
A suspension pin, bush or joint excessively worn
172 occurrences · 3.6% of tests
- 09
A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning
153 occurrences · 3.2% of tests
- 10
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
147 occurrences · 3.0% 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
£168–£515
If every one of this 300'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 300?
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 300 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.