Your RX-8 doesn't need spacers, it needs a wider wheel. 18x8 +50 to 18x9.5 +35 is 34mm out and only 4mm in — and the front caliper, not the fender, is what actually kills bad fitment. 245/40R18, 67.1 hub rings, stay on 18s.
#ThreePieceUS#RX8#wheelfitment#Renesis#rotary#offsetmath#cars#wheels