Thank you so much for the info. Would that ET47 offset spec on any 15x7 five lug bmw wheel work for me? I found this set and was considering it. It's from a 3 series e46 it seems.
http://austin.craigslist.org/pts/4606429561.html Based on that website I would need an offset of ET46. I'm also not clear on what thickness of tire I should use on my 318ti, but I'll look at the tire info sticker on the door jam to see if anything is listed.