75.9%
SEAT Mii
SEAT Mii MOT pass rate and common problems
The SEAT Mii passed 75.9% of its initial MOT tests in 2025, 3.6 percentage points above the 72.3% UK average. The item testers recorded most often was position lamp not working.
Checking a specific car? Its own results, advisories and recorded mileages are in a free MOT history check.
How the Mii compares
Initial MOT tests in 2025, retests excluded. A car that failed and was repaired at the test station counts as a fail.
74%
SEAT average
72.3%
UK average, all cars
The Mii runs 2 points ahead of the SEAT average. It is 4th of the 11 SEAT models in the data. The average Mii arrived at its test 9.6 years old with 54,365 miles recorded.
A pass rate records whether cars met the roadworthiness standard on test day. It is not a reliability score, and part of any gap reflects how old the tested cars were.
Mii MOT pass rate by age
The same 2025 tests split by the car's age at test.
SEAT Mii cars aged 3 to 5 years passed 86.5% of MOT tests. For cars aged 11 years and over that fell to 70.7%, a drop of 15.8 percentage points.
| Age at test | Tests | Pass rate | vs UK average |
|---|---|---|---|
| 3 to 5 years | 2,215 | 86.5% | 14.2 pts above |
| 6 to 10 years | 9,922 | 77% | 4.7 pts above |
| 11 years and over | 6,501 | 70.7% | 1.6 pts below |
That is a steep decline with age, so the headline rate flatters older examples. The UK average of 72.3% covers cars of every age, so compare like with like.
Where Mii failures cluster
Every failure item recorded on SEAT Mii cars in 2025, grouped into the DVSA's test areas.
Lamps, reflectors and electrical equipment and brakes together account for 46% of recorded failure items. These are recorded failures across the model, not faults every car has.
The 10 most common Mii MOT failures
Specific items recorded on SEAT Mii cars that failed their 2025 MOT, as a share of all recorded failure items.
Together these 10 items make up 39.6% of everything testers recorded against failed SEAT Mii cars. The rest is spread across many smaller items, and one failed test often records several at once.
What to look at on a Mii
The recorded failures above, grouped by area, biggest first.
1
Lamps, reflectors and electrical equipment
Recorded most often: position lamp not working, headlamp aim too low and registration plate lamp(s) inoperative in the case of a single lamp or all lamps. 13.8% of failure items.
2
Suspension
Recorded most often: pins and bushes pin or bush excessively worn and coil spring fractured or broken. 7.2% of failure items.
3
Brakes
Recorded most often: service brake performance excessively binding. 4.9% of failure items.
4
Tyres
Recorded most often: tread depth below requirements of 1.6mm. 4.3% of failure items.
The car's own MOT history matters more than any model average. A free MOT history check shows whether a specific Mii has failed on these items before, or had them noted as advisories. Buying one? See the used SEAT Mii buying guide.
Already found one?
Check its finance, write-off, theft, mileage and keeper history with a £15 vehicle history report.
SEAT Mii MOT FAQs
What is the SEAT Mii MOT pass rate?
75.9% of SEAT Mii cars passed their initial MOT first time in 2025, from 18,638 tests. That is 3.6 percentage points above the 72.3% average for all cars, and ranks 252nd of 575 models.
What does a SEAT Mii most commonly fail its MOT on?
The item testers recorded most often on SEAT Mii cars failing their 2025 MOT was position lamp not working, on 5.3% of failure items. Next were service brake performance excessively binding (4.9%) and headlamp aim too low (4.7%).
Which area causes the most SEAT Mii MOT failures?
Across every recorded failure item, the largest area was lamps, reflectors and electrical equipment at 25.7%, followed by brakes at 20.3%.
Do older SEAT Mii cars fail their MOT more often?
SEAT Mii cars aged 3 to 5 years passed 86.5% of MOT tests in 2025, against 70.7% for cars aged 11 years and over.
Does this mean every SEAT Mii has these problems?
No. These are the items testers recorded across every SEAT Mii that failed in 2025. They show where the model most often needs attention, not the condition of any individual car.
How do I see a specific SEAT Mii's MOT history?
Enter its registration on the free Carpeep MOT history check to see that car's own test results, failures, advisories and recorded mileages.
MOT figures are aggregated from the DVSA MOT Anonymised data set for 2025: class 4 initial tests, retests excluded, with failure items from failed tests (advisories and minor defects excluded), licensed under the Open Government Licence v3.0. MOT results describe roadworthiness at test, not mechanical reliability.