75.9%
SEAT Mii pass rate
Used SEAT Mii buying guide
In 2025, SEAT Mii cars passed 75.9% of 18,638 initial MOT tests, 3.6 points above the 72.3% UK average. Here is where it fails and what to check before you buy.
Looking at a specific Mii? Check its finance, write-off, stolen, mileage and keeper history. £15, no account needed.
SEAT Mii MOT record in brief
Initial MOT tests in 2025, retests excluded.
72.3%
UK average, all cars
+3.6
percentage points above average
Ranked on pass rate the Mii sits 252nd of 575 models in the data. SEAT as a brand averaged 74%, so this model runs 2 points ahead of its own brand. SEAT Mii cars aged 3 to 5 years passed 86.5% of MOT tests in 2025; for examples aged 11 years and over that fell to 70.7%.
A pass rate is not a reliability score. The full SEAT Mii MOT record has the pass rate by age, every common failure and how the Mii compares with similar cars.
Mii fuel types
Petrol was the most common fuel among SEAT Mii cars tested in 2025. Diesel made up just 0% of tests.
Where the Mii fails its MOT
Where SEAT Mii cars that failed their 2025 MOT were marked down, as a share of all recorded failure items.
The specific items testers recorded most often were position lamp not working (5.3%), service brake performance excessively binding (4.9%) and headlamp aim too low (4.7%). See every common Mii MOT failure.
These are DVSA failure records across every SEAT Mii that failed, not a claim that every Mii has these problems.
What should you check when buying a used Mii?
The areas above, most common first, and what an MOT tester looks at in each.
1
Lamps, reflectors and electrical equipment
Walk round with every light on: headlights, brake lights, indicators, fog lights and the number plate lamp. Check no warning lights stay on after starting. 25.7% of Mii failure items.
2
Brakes
Make sure the pedal feels firm, the car stops in a straight line, the handbrake holds on a slope and no brake warning light is showing. 20.3% of Mii failure items.
3
Tyres
Check tread depth across the full width of every tyre (the legal minimum is 1.6mm), and look for cuts, bulges and uneven wear. 11.9% of Mii failure items.
4
Suspension
Listen for knocks over bumps, check the car sits level, and look for leaking shock absorbers and split rubber gaiters. 11.9% of Mii failure items.
5
Noise, emissions and leaks
Listen for a blowing exhaust, watch for smoke on start-up and look under the car for oil or fluid leaks. 11.6% of Mii failure items.
None of this replaces the car's own record. Run a free MOT history check on the registration to see every test, advisory and recorded mileage for that car.
What the MOT record doesn't tell you
Knowing SEAT Mii failures cluster around lamps, reflectors and electrical equipment and brakes tells you what to inspect. It tells you nothing about whether the car is safe to buy. An MOT does not show money still owed on the car, a write-off, a theft record or a clocked odometer.
Check the exact Mii you are looking at. One £15 report, instant results, backed by a £30,000 data guarantee. More on the SEAT history check.
- Outstanding finance
- Write-off records
- Stolen markers
- Mileage history
- Previous keepers
Other used SEAT models
The most-tested SEAT models in 2025, with how their MOT pass rate compares with the Mii.
Used SEAT Mii FAQs
Is the SEAT Mii reliable?
MOT data does not measure reliability. It records whether a car met the roadworthiness standard on the day of its test. What it does show is a 75.9% first-time pass rate for the SEAT Mii across 18,638 tests in 2025, above the 72.3% average for all cars.
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; for examples aged 11 years and over that fell to 70.7%. On an older example, the car's own MOT history tells you more than the model average.
What should I check before buying a used SEAT Mii?
On the car itself, start with the areas it most often fails on: lamps, reflectors and electrical equipment, brakes and tyres. Then check the individual car's history: outstanding finance, insurance write-off records, stolen markers, mileage and previous keepers. None of these appear in the MOT record or on the V5C.
How do I check a SEAT Mii's history?
Enter the registration of the specific car. A Carpeep car history check reports outstanding finance, write-off category, stolen markers, mileage history, previous keepers, MOT and tax status, import and export markers and scrapped status in one £15 report.
MOT figures are aggregated from the DVSA MOT Anonymised data set for 2025 (class 4 initial tests, retests excluded), licensed under the Open Government Licence v3.0. MOT results describe roadworthiness at test, not mechanical reliability.