The picture
Gs: a strong MOT record by UK norms
Across 3,797 MOT tests, the Gs returns 89.2% first-time pass — comfortably ahead of the UK fleet average. The single most-logged Major fail is windscreen damage. A tyre with the cords showing and tyre tread under the limit round out the top three. Average tested mileage sits at 73,503, 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
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
81 occurrences · 2.1% of tests
- 02
A tyre cords visible or damaged
58 occurrences · 1.5% of tests
- 03
Tyre tread depth not in accordance with the requirements
56 occurrences · 1.5% of tests
- 04
a brake lining or pad worn below 1.5mm
38 occurrences · 1.0% of tests
- 05
Wiper blade defective
37 occurrences · 1.0% of tests
- 06
A tyre seriously damaged
34 occurrences · 0.9% of tests
- 07
Wiper blade missing or obviously not clearing the windscreen
31 occurrences · 0.8% of tests
- 08
Headlamp reflector or lens slightly defective
27 occurrences · 0.7% of tests
- 09
A shock absorber damaged to the extent that it does not function or showing signs of severe leakage
21 occurrences · 0.6% of tests
- 10
A tyre pressure monitoring system malfunctioning or obviously inoperative
18 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 4 failures
£220–£395
If every one of this GS'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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Build your own retest budget.
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.
Item 01 · Amazon UK
Digital tyre-tread depth gauge
Five quid for a gauge beats £150 for a retest. UK MOT minimum is 1.6mm — most testers fail anything below 2mm to be safe.
Search Amazon UK
Item 02 · Amazon UK
Brake pad measurement gauge
Testers fail pads under 1.5mm. A wear gauge tells you if you've got two months left or two weeks.
Search Amazon UK
Item 03 · Amazon UK
Bosch Aerotwin wiper blades
Cheap wipers fail the test on smear streaks. Bosch Aerotwins last a winter and clear a screen properly.
Search Amazon UK
Buying or keeping a GS?
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 GS 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.