http://www.e90post.com/forums/forumdisplay.php?f=35
I would do the intake first but that's just a subjective call.
Also these sub boards are most useful
http://www.e90post.com/forums/index.php?
Also if you are going to the trouble of modifing it I don't see
why you wouldn't want an aftermarket tune.
http://www.eurotuner.com/techarticle...25i/index.html