I've searched this problem, but can't come up with this problem associated with e53 X5's. At my last brake job I did all four corners with new Powerstop carbon fiber pads and drilled and slotted rotors. Was checking wear on them yesterday and the rears are noticeably worn when compared to the fronts. The fronts have a ton of meat left on them. the rears are about half the amount of pad as the fronts. Anyone experience this situation? 2006 3.0