You will not improve traction be using rims with 10, 10.5, 11 " rims. It will look very good but it is nonsens. Look what startech has done; it works perfect. The BBS Wheels are only for show. My roadster is lowered by H&R Springs. (Front: 8,5x20 ET 38 & 5 mm spacer, rear: 10,5 x 20 ET 30mm & 15 mm spacer). If you lower the crossfire the rear wheels will be with a oblique stand (negative Sturzeinstellung). Please see fotos.