SEAT Mii MOT pass rates & common failures

Every completed first-attempt MOT on a SEAT Mii in Great Britain in 2025 — 18,638 tests. Figures cover every Mii first-tested in 2025, all trims grouped. How the Mii ages, what it fails on, and what mileage is normal, computed directly from the official DVSA record of every test.

Pass rate 2025
75.9%
3.6 points above the class-4 average (72.3%); unadjusted for age — the age-matched comparison is below
Tests analysed
18,638
first tests, 2025
Arrived with a dangerous fault
4.9%
of Mii first tests; national 7.3%
Typical mileage at 10 years
53,750
middle half: 38,750–71,250 miles (2,500-mile-band midpoints)

How many SEAT Mii cars are still on the road?

At the end of 2025, DVLA's register held 18,452 SEAT Mii cars that were taxed or on SORN: 18,199 taxed and 253 on SORN (Statutory Off Road Notification — kept, but declared off the road by the keeper). The MOT figures above count tests; these count cars, across the whole United Kingdom, cars only. SEAT Mii vans, where they exist, are counted by DVLA as goods vehicles and are not in these figures.

Still taxed, end of 2025
18,199
98.6% of the 18,452 Mii cars taxed or on SORN; 18 model variants grouped
On SORN, end of 2025
253
declared off the road by their keepers — 1.4% of that total

How the numbers are moving

The number of taxed Mii cars peaked at 18,879 at the end of 2021 and has since fallen by 680 (3.6%) to 18,199 at the end of 2025. Cars on SORN went from 33 at the end of 2014 to 253 at the end of 2025, up 666.7%. A car leaves the taxed count when it is scrapped, exported or declared off the road; the year-end counts do not say which.

Taxed Mii cars, year by year

Cars of this model taxed and on the road at the end of each year, 2014–2025.

05k10k15k20k2014201620182020202220242025Year (count at the end of the year)Taxed Mii cars, year 2014: 9kTaxed Mii cars, year 2015: 11kTaxed Mii cars, year 2016: 14kTaxed Mii cars, year 2017: 15kTaxed Mii cars, year 2018: 16kTaxed Mii cars, year 2019: 18kTaxed Mii cars, year 2020: 18kTaxed Mii cars, year 2021: 19kTaxed Mii cars, year 2022: 19kTaxed Mii cars, year 2023: 19kTaxed Mii cars, year 2024: 18kTaxed Mii cars, year 2025: 18k18k
View this chart as a table
YearTaxed Mii cars
20148,763
201511,363
201613,610
201715,049
201816,224
201917,536
202017,642
202118,879
202218,711
202318,584
202418,386
202518,199

Mii cars on SORN, year by year

Cars of this model declared off the road at the end of each year, 2014–2025. Its own scale — SORN counts are a fraction of the taxed count.

01002003002014201620182020202220242025Year (count at the end of the year)Mii cars on SORN, year 2014: 33Mii cars on SORN, year 2015: 61Mii cars on SORN, year 2016: 56Mii cars on SORN, year 2017: 65Mii cars on SORN, year 2018: 89Mii cars on SORN, year 2019: 110Mii cars on SORN, year 2020: 123Mii cars on SORN, year 2021: 135Mii cars on SORN, year 2022: 139Mii cars on SORN, year 2023: 160Mii cars on SORN, year 2024: 182Mii cars on SORN, year 2025: 253253
View this chart as a table
YearMii cars on SORN
201433
201561
201656
201765
201889
2019110
2020123
2021135
2022139
2023160
2024182
2025253

Which model years survive

Taxed Mii cars at the end of 2025 by year of manufacture, and each year's share of the 18,199 taxed in all. Every build year holding at least 1% has its own row; the rest share one. 1 taxed Mii car has no recorded year of manufacture and is not in the table, so the rows add up to 18,198. A build year's count depends on how many were sold that year as well as how many have lasted.

Year of manufacture Taxed, end of 2025Share of taxed Mii cars
20211,0335.7%
20202771.5%
20191,2677.0%
20181,2406.8%
20171,4377.9%
20162,17311.9%
20152,62214.4%
20143,07216.9%
20133,38018.6%
20121,6979.3%

Population source: Department for Transport / DVLA vehicle licensing statistics, table VEH0124, updated 15 July 2026; counts of the cars on DVLA's register that were taxed or on SORN at the end of each year shown, United Kingdom, cars only, excluding cars recorded with no model name. SortedCars groups DVLA's model name MII under this model. Contains public sector information licensed under the Open Government Licence v3.0. SortedCars is not affiliated with, or endorsed by, DVLA or the Department for Transport.

How the Mii ages

First-time pass rate by vehicle age, Mii vs all cars, 2025.

SEAT MiiAll cars
50%60%70%80%90%100%3579111315171920Vehicle age (years)SEAT Mii, vehicle age 4: 87.3%SEAT Mii, vehicle age 6: 84%SEAT Mii, vehicle age 7: 82.6%SEAT Mii, vehicle age 8: 80.1%SEAT Mii, vehicle age 9: 74.1%SEAT Mii, vehicle age 10: 73.8%SEAT Mii, vehicle age 11: 75.3%SEAT Mii, vehicle age 12: 70.4%SEAT Mii, vehicle age 13: 70.2%All cars, vehicle age 3: 88.5%All cars, vehicle age 4: 87.2%All cars, vehicle age 5: 86%All cars, vehicle age 6: 83.5%All cars, vehicle age 7: 80.9%All cars, vehicle age 8: 78.2%All cars, vehicle age 9: 74.9%All cars, vehicle age 10: 71.9%All cars, vehicle age 11: 68.6%All cars, vehicle age 12: 65.8%All cars, vehicle age 13: 63.5%All cars, vehicle age 14: 61.2%All cars, vehicle age 15: 59.3%All cars, vehicle age 16: 58.3%All cars, vehicle age 17: 57.2%All cars, vehicle age 18: 57.4%All cars, vehicle age 19: 57%All cars, vehicle age 20: 57.6%SEAT Mii 70.2%All cars 57.6%
View this chart as a table
Age (years)Mii testsMii pass rateAll cars
41,08587.3%87.2%
61,30484.0%83.5%
71,27782.6%80.9%
81,47180.1%78.2%
92,23874.1%74.9%
102,68173.8%71.9%
113,08175.3%68.6%
123,49170.4%65.8%
131,72970.2%63.5%

Better or worse than the average car?

The Mii's pass rate minus the all-cars pass rate at each age, in percentage points. Bars above zero: the Mii beats the average car of that age. Below zero: it trails.

Mii aheadMii behind
-8-4+0+4+8Age 4: +0.1 points vs the average carAge 6: +0.5 points vs the average carAge 7: +1.7 points vs the average car7Age 8: +1.9 points vs the average carAge 9: -0.8 points vs the average car9Age 10: +1.9 points vs the average carAge 11: +6.7 points vs the average car11Age 12: +4.6 points vs the average carAge 13: +6.7 points vs the average car13Vehicle age (years)
View this chart as a table
Age (years)Gap (points)
4+0.1
6+0.5
7+1.7
8+1.9
9-0.8
10+1.9
11+6.7
12+4.6
13+6.7

The Mii fleet on the road, by age

How many took a first MOT in 2025 at each age — the shape of the Mii fleet still in use.

01k2k3k4kAge 4: 1k4Age 6: 1k6Age 7: 1kAge 8: 1k8Age 9: 2kAge 10: 2k10Age 11: 3kAge 12: 3k12Age 13: 1k13Vehicle age (years)
View this chart as a table
Age (years)First tests
41,085
61,304
71,277
81,471
92,238
102,681
113,081
123,491
131,729

What a Mii fails on

Where the failure items land when a Mii fails or needs a fix at test, 2025. Use it as a pre-purchase checklist: these are the areas to look at first.

Lamps, reflectors and electrical equipment25.7%
Brakes20.3%
Tyres12.0%
Suspension11.9%
Noise, emissions and leaks11.6%
Visibility8.1%
Body, chassis, structure5.7%
Seat belts and supplementary restraint systems3.3%

Share of all failure items, 2025 — the 8 biggest categories shown (98.7% of the items); smaller categories are not listed.

The advisories to watch

Where testers most often write "keep an eye on this" for a Mii, 2025 — the faults in the post.

Tyres: 43.2% of advisories43.2%Brakes: 26.2% of advisories26.2%Suspension: 16.1% of advisories16.1%Non-component advisories: 7.1% of advisories7.1%Body, chassis, structure: 2.4% of advisoriesIdentification of the vehicle: 1.9% of advisories
TyresBrakesSuspensionNon-component advisoriesBody, chassis, structureIdentification of the vehicle
View this chart as a table
CategoryShare of advisories
Tyres43.2%
Brakes26.2%
Suspension16.1%
Non-component advisories7.1%
Body, chassis, structure2.4%
Identification of the vehicle1.9%

Petrol, diesel or hybrid Mii?

First-time pass rate for the two most-tested Mii fuel types, 2025, against the all-cars average. Fleet ages differ by fuel — newer fleets help the electrified bars.

50%60%70%80%90%100%all cars 72.3%Petrol: 75.0% of 17,271 tests75.0%Petrol17,271 testsElectric: 87.2% of 1,364 tests87.2%Electric1,364 tests
View this chart as a table
FuelTestsPass rate
Petrol17,27175.0%
Electric1,36487.2%

What mileage is normal for a Mii?

Mileage recorded at test by vehicle age, 2025. The line is the typical (median) Mii; the shaded band holds the middle half. A car far outside the band, in either direction, is worth questions the recorded history can answer.

Typical Mii (median)
0k25k50k75k100k468101213Vehicle age (years)Age 4: typical 23,750 miles (middle half 16,250–31,250)Age 6: typical 28,750 miles (middle half 18,750–41,250)Age 7: typical 36,250 miles (middle half 23,750–48,750)Age 8: typical 41,250 miles (middle half 28,750–56,250)Age 9: typical 46,250 miles (middle half 33,750–63,750)Age 10: typical 53,750 miles (middle half 38,750–71,250)Age 11: typical 58,750 miles (middle half 43,750–78,750)Age 12: typical 66,250 miles (middle half 48,750–86,250)Age 13: typical 71,250 miles (middle half 51,250–93,750)71k mi

Mileage values are midpoints of 2,500-mile bands.

View this chart as a table
Age (years)Lower quarterTypical (median)Upper quarter
416,25023,75031,250
618,75028,75041,250
723,75036,25048,750
828,75041,25056,250
933,75046,25063,750
1038,75053,75071,250
1143,75058,75078,750
1248,75066,25086,250
1351,25071,25093,750

What fails at each age

The Mii's failure mix by age band, 2025 — each band's top categories at their true share of that band's failure items; the pale remainder is everything else. How the mix shifts with age is the point of the chart.

TyresBrakesLamps, reflectors and electrical equipmentSuspensionVisibilityNoise, emissions and leaksEverything else
View this chart as a table
Age bandCategoryShare of the band's failure items
3-5 yrsTyres47.2%
3-5 yrsBrakes18.6%
3-5 yrsLamps, reflectors and electrical equipment14.6%
3-5 yrsSuspension9.5%
3-5 yrsVisibility6.5%
3-5 yrsEverything else3.6%
6-9 yrsBrakes23.0%
6-9 yrsLamps, reflectors and electrical equipment16.6%
6-9 yrsNoise, emissions and leaks16.1%
6-9 yrsTyres15.3%
6-9 yrsSuspension13.9%
6-9 yrsEverything else15.1%
10-13 yrsBrakes25.0%
10-13 yrsLamps, reflectors and electrical equipment16.9%
10-13 yrsSuspension14.5%
10-13 yrsNoise, emissions and leaks13.2%
10-13 yrsTyres11.7%
10-13 yrsEverything else18.7%

More vehicles we've checked

How these figures are computed. Every number on this page is calculated by SortedCars from the DVSA anonymised MOT results dataset (every MOT test in Great Britain — 2025 for single-year figures; trend figures state their span, currently 2023–2025). Where a figure comes from a sample or uses banded values (mileage is banded to 2,500 miles), the page says so beside the figure. Test class 4 only, first tests only — retests are excluded. Class 4 is the car MOT class and also covers car-derived vans, pickups and motorhomes tested to the same standard; where this page says "cars" it means class 4. Pass rate = passes ÷ (passes + failures + pass-after-rectification): a vehicle that failed and was fixed during the visit counts as a fail. Pass rates describe fleets, not individual machines: they reflect how cars were driven, maintained and used as well as how they were built, and beyond recorded mileage none of that is in the data. A well-kept example of a model with a weak average can still pass; a neglected example of a strong one can still fail. No figure is shown for any group with fewer than 500 tests. Alias spellings of a make in the DVSA file are counted under one make name, and all trims and variants of a model are grouped under one model name, using SortedCars' grouping tables. The taxed and SORN counts on this page are the one exception: they are not computed from MOT records but taken from the Department for Transport's vehicle licensing statistics (DfT/DVLA table VEH0124, updated 15 July 2026, Open Government Licence v3.0), which count the cars on DVLA's register that were taxed or on SORN at the end of each year shown, UK-wide, cars only. They describe a model as a whole, grouped under SortedCars' model names, and say nothing about any one car. “Dangerous” is DVSA's statutory defect category (in force since May 2018): a defect posing an immediate risk to road safety — driving the vehicle before repair is an offence. What these figures are for. These statistics are general information about groups of vehicles. They are not advice, a valuation or a recommendation to buy, avoid or price any particular vehicle, and no decision about one car should rest on them alone — check the car itself and its own records. We take care over the calculations, but we cannot guarantee they are complete, current or free of error, and we accept no liability for loss arising from reliance on them. This does not limit any liability that cannot lawfully be limited — see our Terms & Conditions. If you believe any figure on this page is inaccurate, contact us. SortedCars is not affiliated with, or endorsed by, the DVSA or DVLA. DVSA publishes the raw test records; the statistics on this page are SortedCars' own calculations from them. Contains public sector information licensed under the Open Government Licence v3.0.