Very common on 'Epsilon' floorpan SAAB 9-3s and Vauxhall Vectras. But a much wider problem since it's also common on all European makes and models of cars, partly due to the quality of steel, partly due to the way the springs are wound, partly due to the way the springs are finished at the ends, partly due to the way the springs are mounted, partly due to the way the springs are coated and partly due to the proliferation of speed humps, speed cushions and potholes in Britain. Strangely not common in Far Eastern built cars bought and used in Europe.