MOT cost .

Mazda

BT 50

1,268 MOT tests analysed. runs below the UK fleet average — here's where BT 50s pass, fail, and end up on the retest sheet.

That's 8.9 points below the UK fleet average across our 1,988 tracked models — buyers should expect more first-time fails than the typical UK car.

Pass

66.8%

Pass-after-fix

7.3%

Fail

25.2%

Avg miles

112,578

Pass + Pass-after-fix + Fail = 100%

The picture

Bt-50: a below-average pass rate worth digging into

Across 1,268 MOT tests, the Bt-50 returns 66.8% first-time pass — well below the UK fleet average. The single most-logged Major fail is a corroded brake pipe. A number-plate lamp out and windscreen damage round out the top three. Average tested mileage sits at 112,578, 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.

  1. 01

    Brake pipe damaged or excessively corroded

    91 occurrences · 7.2% of tests

  2. 02

    A rear registration plate lamp or light source missing or inoperative in the case of multiple lamps or light sources

    90 occurrences · 7.1% of tests

  3. 03

    Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view

    79 occurrences · 6.2% of tests

  4. 04

    Headlamp reflector or lens slightly defective

    78 occurrences · 6.2% of tests

  5. 05

    A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning

    57 occurrences · 4.5% of tests

  6. 06

    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

    56 occurrences · 4.4% of tests

  7. 07

    A transmission shaft constant velocity joint boot severely deteriorated

    50 occurrences · 3.9% of tests

  8. 08

    Body, cab or chassis excessively corroded at a mounting point

    41 occurrences · 3.2% of tests

  9. 09

    A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc

    40 occurrences · 3.2% of tests

  10. 10

    An obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning

    39 occurrences · 3.1% 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

£58–£205

If every one of this BT 50'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

H7 / W21W bulb pack

A spare-bulb kit lives in the boot. Test morning is not the time to find your stop-lamp's gone.

Search Amazon UK

Item 02 · Amazon UK

Headlight restoration kit

Yellowed lenses fail the light-output test. A restoration kit lifts the haze in an afternoon for £20.

Search Amazon UK

Buying or keeping a BT 50?

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 BT 50 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.