Volkswagen / Audi

The most popular diesel in Europe (Golf, Passat, Octavia, A4). With age the EGR, DPF and dual-mass flywheel show up; the CR injection outlasts the old unit injectors.

Downsized petrol from Golf and Octavia. Early chain-driven versions are known for chain stretch and jumping - a cold-start rattle is your alarm bell.

Passat, Octavia and Tiguan petrol. Gen 2 was famous for oil consumption (rings), gen 3 is far better; the chain and tensioner remain a checkpoint.

A reliability legend. When something does light up, it is usually the VGT turbo, EGR or MAF - all cheap fixes by modern standards.