depending on the clearance probs on the caliper itself, it is possible to "shave" a bit from the offending calipers using a dremmel or angle grinder, whichever falls to ahnd! it makes no difference to the caliper anyway if taken in small doses, and is usually only aq thin sliver needed to save those expensive wheels from catching! i'd avoid all spacers that aren't hub adapters for pcd unless hub centric, and then only if completely needed, as spacers of anything above 10mm put undue stresses on the front wheel bearings, and in extreme cases, ball joints too!