Nope. They are indeed interchangeable, but you still have to grind off the mounting studs for the hangers, replace them with longer bolts that can accommodate the beefier M3 hangers. Same story with the 325; that's what I had to do when I went with the M3 catback. Some people use the stock hangers, but they break in no time due to the heavier weight of the M3 muffler.