yeah i don't think there's going to be a marked performance increase over the 135i. i haven't done a whole lot of research on the subject, but if i'm not mistaken it gets the 335is twin turbo n54, a fancy body kit and wheels and some m badges, maybe a few suspension tweaks thrown in.

i'll take an e92 m3, thanks. unless you just REALLY want a turbo 6 over a v8... which, to say the n54 responds very well to modification. $895 gets you 60whp right off the bat...

http://www.cobbtuning.com/products/?id=5833