GENUINE BMW M PERFORMANCE REAR DIFFUSER, CARBON FIBRE. We offer for sale this genuine BMW 1 Series (F40) item, new and unused in original BMW packaging. THIS LISTING IS FOR. 1 x M Performance Rear Diffuser, Carbon Fibre. (Carbon fibre tow hitch cover and plastic rivets included). Some specifications of the following BMW vehicles. Brand new, unused item in original packaging. Buyers outside of the United Kingdom.