The Aisin automatic of the transverse engine VAG models locks the torque converter across a wide slip range, which gains on fuel consumption but loses on the life of the friction lining. The sign of wear is a vibration or "buzzing" felt at lock-up, and the lock-up cycling on and off.

Leaves and debris block the drains of the water collector under the windscreen. The standing water seeps into the cabin through the bulkhead grommets, and it also reaches the electronics box sitting in the right hand side of the collector. Once that box is wet, the electrical faults come from there.

The G62 sensor tells the engine control unit how hot the coolant is. If it is faulty, the control unit thinks a warm engine is cold, and runs it rich: hard warm or cold starting, a rough idle, markedly increased fuel consumption, and a dash temperature gauge that jumps around or never reaches its usual reading. The part is cheap and can be replaced in half an hour: the trouble is that many people do not recognise it and replace an injector or a lambda sensor instead. If the fault persists, the rich mixture can destroy the catalytic converter too.

The cable of the window regulator jams or tangles, and the holding clamp (originally plastic) breaks, dropping the glass into the door. It is often preceded by a crunching noise. The repair requires removing the door trim; the refurbishment kits come with a metal clamp, precisely because the factory plastic is the weak point.

From the late nineties to around 2006, petrol engines used a secondary air pump to blow fresh air into the exhaust on a cold start, so the catalytic converter reaches operating temperature faster. The impeller of the pump rusts or its bearing seizes, soot clogs the combination valve (N112), and the rubber hoses crack. The control unit then stores the `P0411` code. It barely affects driving, but the engine warning light is on, and the emissions test can fail because of it, and the roadworthiness test with it.