Akrapovic 21-22 BMW M3 (G80) / M4 (G82, G83) Rear Carbon Fiber Diffuser - High Gloss BlackDI BM CA 9 GB For extra visual impact, there is the option to add a hand crafted carbon fibre diffuser. Produced in house, this lightweight accessory with ABE type approval is designed to show off the tailpipes of the Akrapovi exhaust at their absolute best. A new feature is offered with this updated version of the diffuser: a high gloss black painted frame integrates the diffuser with the rear part of the vehicle.