I've just got some 225/40/18 M Sport alloys for my 320 coupe (51plate). They all fit fine (no touching when straight or full lock) but when i drive in a straight line even at low speed, theres an obvious clunk sound from the front two...sounds like metal on metal and once a turn (not rubbing constantly), I've looked all around the wheel and cant see ANY contact between wheel and arch/disc etc. Any ideas would be brill!