Just phoned mstyle and it wasnt the resistors. They have fixed the problem though it seems. The problem was that the kits came with "booster inverter boxes" which boost the brightness of the lights above the normal 5 watts to get the real angel eye brightness. The X5 is apparently very sensitive to the ultrasonic signals coming from these sensors which was sending the PDC beserk. The manufacturer has now provided new booster inverter boxes which has sorted the problem. They are fitting them to an X5 this week and are going to send me some pictures today hopefully - will of course post them up!!