You need 225/35 and 265/30 with some camber in the rear.
I ran 18x11" et20 265/35 w/ -3 camber on E90 LCI, so 11" et25 on pre-LCI will be 13mm less than this (it will be true flush):
http://farm5.static.flickr.com/4039/...ccdae763_b.jpg
I now have 18x9.5" et19 225/40 and 18x11" et32 265/35 w/ about -2.5 camber on E90 LCI, which is quivalent to 11" et24 on pre-LCI:
http://robszot.net/wp/wp-content/upl.../12/rearts.jpg