BMW 645CI CUSTOM EXHAUST
work done; left stock resonators, took out dual resonator and replaced it with a magnaflow xpipe, upped the pipping to 2 1/4" and magnaflow mufflers with a little bit bigger tips. cost=740 after taxes and install
BMW 645CI Catback MagnaFlow Exhaust Part # 16560
Sounds just right to me not to loud even with the top down. It sounds even
better when driving it gets a bit louder and deeper.
BMW 645 custom exhaust by DSpeed
BMW 645CI Remus Exhaust
BMW 645 coupe sound