Look what I found online:
I'm going to bite the bullet and order for the 35i.
I took a bunch of under-car exhaust pictures and they look identical. The mounting points are 100% the same but the only question is if the pipe will thread through one of the rear chassis braces. Have an email out to a BMW parts guy now and we will see, but I'm 99% sure it will fit - perhaps with the minor modifications.