What should I look for in a used BMW 3 Series sports?
The roof is mechanical poetry in motion, but how reliable it will prove to be in the long term is a big question. Check the roof works correctly, with no squeaks, groans or jerky movements when it's raised or lowered. Also check for signs of water leaks when the roof is in place, or water damage caused by owners accidentally leaving the roof down in the rain.
The 320i engine can suffer from crankshaft issues, and will require dealer attention, while the 320d's engine can be a little lumpy at idle. Dealers can reprogramme the ECU, but this doesn't always cure the problem.
Other issues centre on cabin squeaks and rattles - especially around the driver side rear seat, and a glitch with the automatic gearbox, which can be jerky at low speed when in manual mode. The Bluetooth phone integration is notoriously tricky to set up, so contact a dealer for advice.