Land  Rover Discovery is the most unreliable used car, and Citroën the least reliable make, according to 'What Car?' readers... By Robin Roberts. The 2004-2017 Discovery model scored just 47.8 per cent in the 2023 What Car? Used Car Reliability Survey, of 25,000 vehicle owners. Worst brand was Citroën. The most reliable used car in the survey was the Honda Jazz (2015-2020) which scored 100 … [Read more...]