Gone is the unsightly sagging OE muffler of the M2 Competition. Replaced by a sleek and nearly invisible Dinan system making the hindquarters pleasing to the eye once again. The system, constructed of brushed T304 stainless steel and TIG welded with immaculate color displays beautiful artisanship even if it is hidden from view. What is viewable are impressively large quad 4" (102mm) exhaust tips. Available in polished stainless or matte black, the signature Dinan straight cut tips offer a much more agreeable, and aggressive, focal point than the stock setup. With the outward styling and look enhanced, improvement upon the raspy sound of the S55 motor was necessary. To accomplish this an overhaul of many facets of the stock system needed to happen. The internal baffling of the can has been completely redesigned to allow a more Dinan inspired note to be heard (deeper and throatier). The piping has also enlarged to allow freer flow and bring the tone even deeper yet. While these things all make the system a respectable representation of a Dinan M exhaust, what really sets the system apart is the incorporation of an 'X' in place of the factory resonator. Not only does the overall volume increase, but the crossover allows for a refined and smoothened exhaust note complete with a perfect mix of exotic undertones and raw aggression. Combined, these features transform the raspiness of the S55 into a more agreeable Dinan inspired aural experience that keeps you wanting more.