I had plans to intall the Mr. 5 like DIY CAI on my 135i, but there appears to be much less room for the filter and the Power Steering res bracket will have to go completly (unlike what is possible on the 335)
See cross post to 135 section here (Post #32):
http://www.1addicts.com/forums/showthread.php?t=537794
Anyone been able to make this work on the 135i?