2018 SEAT Mii MOT pass rate, common failures & what to check

In 2025, 82.6% of SEAT Miis first used in 2018 passed their MOT first time, against 80.9% for all cars first used in 2018. Across 3,813 Mii first tests from 2023 to 2025, the most common failure areas were lamps and electrical equipment, visibility (wipers, washers and windscreen) and tyres.

This page analyses first MOT tests for SEAT Miis first used in 2018 (all trims grouped): 2021 to 2025 for the pass-rate trend, and 2023 to 2025 for the failure and advisory analysis — plus what is worth checking before you buy one.

Data: DVSA anonymised MOT tests to December 2025 · Calculated by SortedCars · Updated October 2026

Passed first time, 2025
82.6%
of 1,277 first tests; all cars first used in 2018: 80.9%. Fixed-at-the-test counts as a fail
Tests analysed
3,813
first tests, 2023–2025; 1,277 in 2025
Clean pass, 2025
51.5%
of 1,277 first tests in 2025, passed with no advisory and no minor defect recorded
Typical mileage, tested in 2025
35,500
middle half: 24,000–49,000 miles; all cars first used in 2018: 52,000

How the 2018 SEAT Mii MOT pass rate has changed

Share of first tests passed in each year, Miis first used in 2018 against all cars first used in 2018 (any make or fuel; not adjusted for mileage, fuel or use). In 2025 the Mii figure was in line with the all-cars figure.

2018 MiiAll cars first used in 2018
80%90%20212022202320242025Test year (first tests)All cars first used in 2018, test year 2021: 87.6%All cars first used in 2018, test year 2022: 86.3%All cars first used in 2018, test year 2023: 84.2%All cars first used in 2018, test year 2024: 82.5%All cars first used in 2018, test year 2025: 80.9%2018 Mii, test year 2021: 89.1%2018 Mii, test year 2022: 85.6%2018 Mii, test year 2023: 85%2018 Mii, test year 2024: 84.5%2018 Mii, test year 2025: 82.6%82.6%80.9%
View this chart as a table
Test year2018 MiiAll cars first used 2018Mii first tests
202189.1%87.6%1,286
202285.6%86.3%1,268
202385.0%84.2%1,261
202484.5%82.5%1,275
202582.6%80.9%1,277

Common 2018 SEAT Mii MOT failures

Share of the 609 failed first tests (2023–2025) with at least one failure in each area. A test can fail in more than one area, so the shares add up to more than 100%.

Lamps, reflectors and electrical equipment35.3%
Visibility26.3%
Tyres24.3%
Brakes16.6%
Suspension11.0%
Noise, emissions and leaks5.7%

Most common failure items

DVSA failure itemShare of failed first testsTests
Wipers: does not clear the windscreen effectively16.9%103
Headlamp aim: too low9.5%58
Position lamp: not working8.2%50

Item names are DVSA’s own wording. 2023–2025 combined.

What to check on a 2018 SEAT Mii before buying

The three areas where failed first tests most often had a fault, 2023–2025.

  1. Lamps and electrics. Ask someone to watch while you work the brake lights, indicators, sidelights, dipped and main beam, and the number-plate lamps.
  2. Wipers and windscreen. Worth checking that the wipers clear the screen cleanly, that the washers work, and that there are no chips or cracks in the driver’s view.
  3. Tyres. Worth checking the tread depth across the whole width of each tyre, and the sidewalls for cuts, cracks and bulges.

Common 2018 SEAT Mii MOT advisories

Advisories are points the tester noted that did not fail the car. Most common on 2018 Miis, as a share of all 3,813 first tests, 2023–2025.

DVSA advisory itemShare of first testsTests
Tyre condition: slightly damaged/cracking or perishing16.2%618
Tread depth: worn close to legal limit/worn on edge10.5%401
Suspension arm pins and bushes: pin or bush worn but not resulting in excessive movement4.5%172
Brake discs: worn, pitted or scored, but not seriously weakened4.1%155
Brake pads: wearing thin3.8%145

Questions about the 2018 SEAT Mii MOT

What is the MOT pass rate of a 2018 SEAT Mii?

In 2025, 82.6% of Miis first used in 2018 passed their MOT first time, against 80.9% for all cars first used in 2018. A car fixed during the test counts as a fail.

What does a 2018 Mii most often fail its MOT on?

Lamps and electrical equipment (in 35.3% of failed first tests, 2023–2025), visibility (wipers, washers and windscreen) (26.3%) and tyres (24.3%). The single most common item was “Wipers: does not clear the windscreen effectively” (16.9%).

How often does a 2018 SEAT Mii fail its MOT?

In 2025, 17.4% of first tests on Miis first used in 2018 did not pass first time: 12.7% failed, and a further 4.7% had a fault fixed during the test (counted as a fail here). Across 2023–2025, 609 of 3,813 first tests did not pass first time.

What are the most common 2018 SEAT Mii MOT advisories?

“Tyre condition: slightly damaged/cracking or perishing” (on 16.2% of first tests, 2023–2025), “Tread depth: worn close to legal limit/worn on edge” (10.5%), “Suspension arm pins and bushes: pin or bush worn but not resulting in excessive movement” (4.5%), “Brake discs: worn, pitted or scored, but not seriously weakened” (4.1%) and “Brake pads: wearing thin” (3.8%).

Is a 2018 SEAT Mii reliable?

An MOT pass rate shows what failed at the test, not how reliable a car is. For this group of cars the first-time pass rate went from 89.1% in 2021 to 82.6% in 2025. For one particular car, its own MOT history matters more than the average.

Other cars first used in 2018

The most-tested cars from the same year. Each page uses the same method.

2018 Ford Fiesta MOT statistics · 2018 Volkswagen Golf MOT statistics · 2018 Vauxhall Corsa MOT statistics · 2018 Ford Focus MOT statistics · 2018 Nissan Qashqai MOT statistics

How the 2018 SEAT Mii MOT data is calculated

Every number on this page is calculated by SortedCars from DVSA’s anonymised MOT test data for Great Britain, 2021–2025. “2018 Mii” means a SEAT Mii whose date of first use falls in 2018 (67, 18 and 68 plates), all trims grouped. Class 4 vehicles, first tests only — retests are not counted. Pass rate = passed ÷ all first tests; a car with a fault fixed during the test (PRS) counts as a fail. Our national first-test pass rate matches DVSA’s published figure (table DVSA/MOT/01) to within 0.04 points in every year. Clean pass = passed with no advisory and no minor defect recorded. Mileage is the reading recorded at the test. Comparisons are with all cars first used in 2018, any make or fuel, and are not adjusted for mileage, fuel or use. Failure and advisory item names are DVSA’s own wording. No figure is shown for fewer than 500 tests; an item is shown only if it appears on at least 50 tests and 1% of the base. Pass rates describe a group of cars, not one car: a well-kept example can pass and a neglected one can fail. This page is general information, not advice about any particular vehicle; always have a used car inspected before you buy. SortedCars is not affiliated with or endorsed by DVSA. You can check any car’s MOT history free on the official service: gov.uk/check-mot-history. Contains public sector information licensed under the Open Government Licence v3.0.