[HighlyMedicated]

You need to cut your stock exhaust before the 2nd cats to install a MPE and fit it over the stock and clamp it with the clamps provided, easy to do but not exactly bolt on. So if longer you need to cut a longer piece for f80 but for f83 it should be the same, everything will fit the same. The added material for convertibles are integrated within the car not hanging low or else it would possibly be damaged and that is a lawsuit bmw does not want! I would install the muffler first then guage how much needs to be cut to fit the mpe midsection on. Enjoy, its a different car with mpe and the titanium muffler !