Daihatsu Sirion 2003: MOT failure rate for its age
40.6% of 880 MOT tests of the Daihatsu Sirion first registered in 2003 failed at the first attempt (2019–2024; retests excluded). Against this model's own normal rate at the same ages the index is 98.5 (95% CI 88.3–108.7; 100 = normal for this model at that age): the 2003 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.
| Measure | Value | Unit | Compared with | Years | Tests |
|---|---|---|---|---|---|
| Failed first time | 40.6 | % | all ages tested | 2019–2024 | 880 |
| Index against this model at the same age (95% CI 88.3–108.7) | 98.5 | index | 100 = normal for this model at that age | 2019–2024 | 880 |
| Rank among this model's 10 build years | 5 | of 10 | 1 = fails least for its age | 2019–2024 | 880 |
| Tested in 2024 | 123 | tests | median 69,443 miles | 2024 | 123 |
Data release dvsa-2024-v2 (24 Sep 2026) · page updated 30 Sep 2026 · full dataset (v5).
How does the 2003 Daihatsu Sirion fail at each age?
Cars built in 2003 were tested at ages 16 to 21 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.
| Age | Tests | Failed, % | 95% interval | Normal for this model at that age, % | Index (100 = normal) |
|---|---|---|---|---|---|
| 16 | 293 (rough estimate) | 42 | 36.5–47.7 | 41.8 | 100.5 |
| 17 | 220 (rough estimate) | 39.5 | 33.3–46.1 | 40.6 | 97.3 |
| 18 | 195 (rough estimate) | 41.5 | 34.9–48.6 | 41.2 | 100.8 |
| 19 | 172 (rough estimate) | 38.4 | 31.4–45.8 | 40.9 | 93.8 |
| 20 | 156 (rough estimate) | 38.5 | 31.2–46.3 | not available | not available |
| 21 | 123 (rough estimate) | 43.9 | 35.4–52.7 | not available | not available |
Source: DVSA MOT bulk data · Window: 2019–2024 · n = 1,159 (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 2003 Daihatsu Sirion?
The most common failure group on cars built in 2003 is lamps, reflectors and electrical equipment: 36.9 items per 100 first tests, against 20.9 across all build years of the Daihatsu Sirion. These counts are not age-adjusted: cars built in 2003 were tested at ages 16 to 21.
| Failure group | Built 2003, per 100 | All build years, per 100 | Items |
|---|---|---|---|
| Lamps, reflectors and electrical equipment | 36.9 | 20.9 | 428 |
| Suspension | 36 | 25.1 | 417 |
| Body, chassis, structure | 17.6 | 11.4 | 204 |
| Brakes | 17.2 | 14.7 | 199 |
| Noise, emissions and leaks | 14.8 | 5.5 | 172 |
Source: DVSA MOT bulk data · Window: 2019–2024 · n = 1,159 (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 2003 compare with the years around it?
Among the 10 published build years of the Daihatsu Sirion, 2003 ranks 5 (1 = fails least for its age). 2002: index 97.6. 2004: index 104.8.
| Build year | Index (100 = normal) | 95% interval | Verdict | Tests |
|---|---|---|---|---|
| 2001 | 108.8 | 92.5–125.2 | no different (rough estimate) | 358 |
| 2002 | 97.6 | 87.1–108.1 | no different (rough estimate) | 799 |
| 2003 | 98.5 | 88.3–108.7 | no different (rough estimate) | 880 |
| 2004 | 104.8 | 93.9–115.8 | no different (rough estimate) | 847 |
| 2005 | 104.8 | 100.5–109.1 | worse | 5,804 |
| 2006 | 102.0 | 97.6–106.3 | no different | 5,690 |
| 2007 | 99.9 | 96.6–103.3 | no different | 10,014 |
| 2008 | 98.4 | 95.4–101.4 | no different | 12,903 |
| 2009 | 95.2 | 90.7–99.7 | better | 5,986 |
| 2010 | 95.0 | 80.2–109.8 | no different (rough estimate) | 573 |
Source: DVSA MOT bulk data · Window: 2019–2024 · n = 43,854 (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). Daihatsu Sirion 2003 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/daihatsu-sirion/2003/
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.
Other pages for this model
Daihatsu Sirion 2001 · Daihatsu Sirion 2002 · Daihatsu Sirion 2004 · Daihatsu Sirion 2005 · Daihatsu Sirion 2006 · Daihatsu Sirion 2007 · Daihatsu Sirion 2008 · Daihatsu Sirion 2009 · Daihatsu Sirion 2010 · Daihatsu Sirion in the Netherlands · Daihatsu Sirion by postcode area · Daihatsu Sirion body, chassis and structure failures · Daihatsu Sirion brakes failures · Daihatsu Sirion vehicle identification failures · Daihatsu Sirion lamps, reflectors and electrics failures · Daihatsu Sirion noise, emissions and leaks failures · Daihatsu Sirion seat belts and airbags failures · Daihatsu Sirion steering failures · Daihatsu Sirion suspension failures · Daihatsu Sirion tyres failures · Daihatsu Sirion visibility failures