Originally Posted by MDORPHN
I believe that it's differently configured than the N54 resonator.
And, it's just not the subframe bushings; the 1M has an entirely different subframe and diff than the 135i. As you know, it's off of the E9x M3.
Based on pix in HP Autowerks separate thread on the Berk Technology midpipe, it would appear that there's plenty of room to accomodate the stock N55 midpipe.
Might just have to consider picking one up.