Seat Mii 2020: MOT failure rate for its age

12.9% of 559 MOT tests of the Seat Mii first registered in 2020 failed at the first attempt (2019–2024; retests excluded). Against this model's own normal rate at the same ages the index is 104.9 (95% CI 80.7–129.2; 100 = normal for this model at that age): the 2020 build year is no different from other years of the same model at the same age. This is a rough estimate from a smaller sample.

Seat Mii built in 2020 at a glance
Measure	Value	Unit	Compared with	Years	Tests
Failed first time	12.9	%	all ages tested	2019–2024	559
Index against this model at the same age (95% CI 80.7–129.2)	104.9	index	100 = normal for this model at that age	2019–2024	559
Rank among this model's 9 build years	6	of 9	1 = fails least for its age	2019–2024	559
Tested in 2024	281	tests	median 18,669 miles	2024	281

Built 2020 against Seat Mii normal for the age: first-time MOT failure share at each age, age 3: 14.7% vs 10%; age 4: 11% vs 14.5%. Axis from 0% to 20%. DVSA MOT bulk data, 2019–2024.

Check a 2020 Seat Mii by registration · All Seat Mii MOT statistics · Download the build-year table (CSV)

Data release dvsa-2024-v2 (24 Sep 2026) · page updated 30 Sep 2026 · full dataset (v5).

How does the 2020 Seat Mii fail at each age?

Cars built in 2020 were tested at ages 3 to 4 between 2019 and 2024. Each row compares their first-time failure share with what this model normally shows at that age, after allowing for the overall failure level of each test year.

Seat Mii built 2020: first-time MOT failure by age, against the model's normal rate at that age (2019–2024)
Age	Tests	Failed, %	95% interval	Normal for this model at that age, %	Index (100 = normal)
3	278 (rough estimate)	14.7	11.1–19.4	10	147.3
4	281 (rough estimate)	11	7.9–15.2	14.5	76

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 559 (initial tests) · Method: normal rate = this model's first-time failure share at that age across its build years (cells of 400+ tests), adjusted for each test year's overall level; cells of 30+ tests, under 500 marked rough · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV

What fails most on the 2020 Seat Mii?

The most common failure group on cars built in 2020 is tyres: 10.3 items per 100 first tests, against 5 across all build years of the Seat Mii. These counts are not age-adjusted: cars built in 2020 were tested at ages 3 to 4.

Failure items per 100 first tests, Seat Mii built 2020 against the Seat Mii in all build years (2019–2024, not age-adjusted)
Failure group	Built 2020, per 100	All build years, per 100	Items
Tyres	10.3	5	58

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 562 (initial tests of this build year) · Method: failure items grouped by DVSA's top-level defect groups, per 100 initial tests; groups with 30+ items · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV

How does 2020 compare with the years around it?

Among the 9 published build years of the Seat Mii, 2020 ranks 6 (1 = fails least for its age). 2019: index 76.8.

Seat Mii build years: index against the model at the same age (2019–2024)
Build year	Index (100 = normal)	95% interval	Verdict	Tests
2012	107.5	103.5–111.5	worse	10,713
2013	105.7	102.8–108.6	worse	21,297
2014	92.0	89.0–95.0	better	18,739
2015	100.0	96.5–103.5	no different	16,223
2016	108.2	103.9–112.5	worse	13,470
2017	94.9	89.4–100.4	no different	7,777
2018	94.6	87.7–101.6	no different	5,080
2019	76.8	69.4–84.2	better (rough estimate)	3,992
2020	104.9	80.7–129.2	no different (rough estimate)	559

Source: DVSA MOT bulk data · Window: 2019–2024 · n = 97,850 (initial tests) · Method: observed failures against those expected for the same model at the same ages, test-year level adjusted; verdict follows the printed one-decimal bound · Updated: 30 Sep 2026 · Release: dvsa-2024-v2 · CSV

How to cite this page

MOT Risk Index (2026). Seat Mii 2020 MOT statistics (data release dvsa-2024-v2; full dataset motriskindex-families-2024-v5, DOI 10.5281/zenodo.22975051), updated 30 September 2026. motriskindex.co.uk/cars/seat-mii/2020/

How every figure is calculated: methodology. Age, test year and build year are tied together (age = test year − build year), so the test-year level is taken as observed, not estimated.

Seat Mii 2020: MOT failure rate for its age

How does the 2020 Seat Mii fail at each age?

What fails most on the 2020 Seat Mii?

How does 2020 compare with the years around it?

How to cite this page

Related pages

Other pages for this model