What London cars fail on

Methodology

DVSA's separate failure-item archive joined by test ID to class 4 initial tests for vehicles kept in the eight London postal areas. Retests and the twelve boundary-straddling postcode areas are excluded. Counts are REASON-FOR-REJECTION RECORDS, not vehicles: one test can contain several defects, minor items and advisories, so records cannot be added and described as the number of cars failing. The main ranking includes failed items only; the severity view separately retains advisory, minor, major and dangerous inspection records. Current DVSA item-detail and hierarchy lookups assign each record to its published inspection system. Changes to the MOT regime in 2018 limit long-run comparison.