That design does not look very efficient and looks as though it caters to those looking for a quad exhuast look and nothing more.
It could be less restrictive than the standard sport exhuast, but at what price. Give me a break!
(Waitlist): #1 M2CS
(Current): 2016 F15 X5 3.5xdrive - 2016 F30 340xi M-Sport
(Past): 2013 535i xdrive - 2008 E92 M3
2006 E90 325i - 2002 E46 325xi
1991 E30 325i