I have now had the Z4 E89 a couple of weeks, it's just been serviced and apart from needing a new hall sensor somewhere in the hood mechanism it has a clean bill of health. so now to replacing those run flats. Michelin PS4 and Falken keep being recommended but I would appreciate your experiences/advice. I would just like a more comfy ride, I know the Z is a sport's car but feel sure it can be improved. The wheel size is 225 x 45 x 17 x 4no which should help!