GENUINE BMW M PERFORMANCE REAR DIFFUSER, MPA, CARBON FIBRE, 51192459740. We offer for sale this genuine BMW 3 Series (G20, G21) item, new and unused in original BMW packaging. THIS LISTING IS FOR. 1 x M Performance Rear Diffuser, MPA, Carbon Fibre. Some specifications of the following BMW vehicles. 3′ G20 Sedan (01/2018 -). 3′ G21 Touring (10/2018 -). Brand new, unused item in original packaging. Buyers outside of the United Kingdom.