This is the M Sport Exhaust (which is also on the Competition Package aka Competition Exhaust).
Part number 18308092607 is the MSport assembly that includes the front 2 clamps.
You will also need (2) Two of 18307560815 Butt-Butt Clamps as you can see in the pic below. BMW welded a short piece into the end of each pipe on the MSport exhaust for an easier installation.
Here are stock exhaust resonator vs M Sport / Competition exhaust resonator photos.
Stock resonator:
M Sport / Competition exhaust resonator (showing less perforations than stock resonator):
INSTALL PICS
VIDEOS
Stock exhaust
M Sport / Competition Exhaust
DECIBELS
0 dB gain at idle
0 dB gain at 2000 rpm hold (basically, a high idle)
6dB gain with stationary throttle blips.