The Akrapovi? Evolution and Slip-On line exhaust systems can be further enhanced with an optional hand-crafted carbon-fiber rear diffuser. Developed by Akrapovi?’s Design Department, this stunning diffuser, crafted from materials developed through Akrapovi?’s racing involvement, is designed to perfectly fit the lines of the unique tailpipes of the Slip-On or Evolution systems, as well as complement the sleek and sporty shape of the BMW.