One of my rears is also showing some marks eminating from the centre hub. I will be expecting a replacement under warranty as the car has only completed 14500 miles
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2014 X3 30d Lci M Sport in Black Sapphire. Pro Nav, Black Leather,Adaptive Xenons, Extended Storage, Lighting Package, 19" Staggered (622M) summer wheels, 17" style 304 winter alloys