Akrapovic F8X M3 / M4 Carbon Rear Diffuser - GlossThe Akrapovi Evolution and Slip On line exhaust systems can be further enhanced with an optional hand crafted carbon fiber rear diffuser. Developed by Akrapovis R&D Department, this stunning diffuser, crafted from materials developed through Akrapovis 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.