According to this:
https://app.bmw.co.za/dws/VTS/servle...modelCode=UC92
vs
http://www.2addicts.com/forums/attac...9&d=1381284592
The weight of the 135i coupe is IDENTICAL to the M235i. So the comparison above is incorrect.
Actually pretty disappointing they couldn't shave off any weight at all. Coming from a tuned N54 135i, don't think there's going to be much improvement in upgrading. Perhaps better tuned suspension/ handling, that's about it.