Damp or soaked carpets, misted windows, and electrical faults that come and go as water reaches the control modules under the seats and in the footwells. The drains in the plenum chamber under the windscreen block with leaves and debris, and water then overflows into the cabin. The comfort control module sits low enough to be soaked, which is where a cheap fault turns expensive.
Check: Lift the carpets front and rear and press for damp, check under the seats for corroded module connectors, and clear the plenum drains yourself before you buy.
ElectricalcommonDetectable at viewingevidence: documented80–200k km
Headlights, indicators, windows, wipers and central locking stop working at once, usually right after a battery change or a jump start. The module's memory corrupts when supply voltage dips. It is the single most common electrical failure on this generation.
Check: Test every window, both mirrors, the wipers, all exterior lights and the central locking before you drive. If any cluster of these is dead, this is why.
ElectricalcommonDetectable at viewingevidence: documented
Black screen, rebooting, refusal to read the drive, non-functioning navigation. The early CCC unit's hard drive and mainboard fail with age. Later CIC units are more reliable.
Check: Turn it on and use it for a few minutes: navigation, radio, settings. Reboots during that window are the fault showing itself.
ElectricaloccasionalDetectable at viewingevidence: documented
A cold misfire or judder, the engine seeming to run on three cylinders when cold, lumpy idle and a misfire warning that often clears as it warms. Most often the injector wiring loom chafes through from engine vibration and gives an intermittent signal; separately the pump-düse unit injectors themselves wear. Diagnose which before spending.
Check: Start it cold and feel for a stumble, then read the injector quantity-deviation values on a diagnostic to find the offending cylinder; inspect the loom for chafing.
ElectricaloccasionalPartly detectableevidence: documented120–250k km
Random electrical faults, warning lights that come and go, a battery that dies again within a year. The car's power management must be told a new battery was fitted. Cheap replacements are routinely fitted without coding, which then overcharges or undercharges the new battery.
Check: Ask when the battery was changed and whether it was registered. A car with a new battery, no registration and a scatter of odd electrical faults usually just needs coding.
ElectricalcommonPartly detectableevidence: documented