BMW S55 Single Exit Exhaust For BMW F80 M3, F82 M4, F83 M4 - ARM MotorsportsThe ARM S55 Single Exit Exhaust is the perfect fit if you're looking for an aggressive sounding, lightweight, flame throwing exhaust setup for your F8X! Designed specifically for track use, this exhaust system produces an aggressive exhaust note that will turn heads on and off the track. The purpose of the ARM S55 Single Exit Exhaust can be summed up in one word, FUNCTION. The goal of the ARM S55 Track exhaust is to get the exhaust gasses to the rear