Quickly follow this link, and scroll down: http://www.bimmerfest.com/forums/showthread.php?t=549685
They have pics of the different exhauses, on there you will see how yours look, and also how the 325 one looks.
I see on there that indeed yours have a sensor after the one cat in the exhaust, but my 325 doesnt.
SO monst likely you will have to get a mini-cat fittet, but go see Kobus.
Good luck.