Across 17,683 MOT tests of the SEAT Mii in the DfT's 2023 MOT data (initial tests, retests excluded), 21.0% failed — about 1 in 5. The parts that fail most are lights and electrics (7.1% of tests), brakes (5.6%), wipers, windscreen and mirrors (4.2%), tyres (4.0%) and body, chassis and structure (2.3%).
Allowing for age and mileage, the SEAT Mii has 3% fewer MOT failures than the average car of the same age and mileage.
The MOT checks safety and emissions items — brakes, suspension, steering, lights, tyres, body structure and exhaust emissions. It does not test engines, gearboxes or most electronics, so those faults only show up here when they cause an emissions failure or a leak.
Mii (2012–2020)
MOT: 21.0% of 17,683 initial tests failed — 3% fewer failures than the average car of the same age and mileage
| # | Part / area | Share of MOT tests failing |
|---|---|---|
| 1 | lights and electrics | 7.1% |
| 2 | brakes | 5.6% |
| 3 | wipers, windscreen and mirrors | 4.2% |
| 4 | tyres | 4.0% |
| 5 | body, chassis and structure | 2.3% |
Questions
What fails most on a SEAT Mii at MOT?
The most common MOT failure is lights and electrics: 7.1% of SEAT Mii MOT tests in the 2023 data failed on lights and electrics. Next come brakes (5.6%) and wipers, windscreen and mirrors (4.2%).
How often does a SEAT Mii fail its MOT?
21.0% of SEAT Mii MOT tests in the 2023 data failed (about 1 in 5), counting initial tests only, across 17,683 tests. Allowing for age and mileage, that is 3% fewer MOT failures than the average car of the same age and mileage.
Is the SEAT Mii reliable?
On MOT results, the SEAT Mii has 3% fewer MOT failures than the average car of the same age and mileage. MOT data covers safety and emissions items, not engines or gearboxes.
Does this SEAT Mii data cover engine and gearbox problems?
No. The MOT checks safety and emissions items — brakes, suspension, steering, lights, tyres, body structure and exhaust emissions. It does not test engines, gearboxes or most electronics, so those faults only show up here when they cause an emissions failure or a leak.