I want to get CSL's for my soon to have new 328i. What backspacing do i need to get? Can I use the e46 rims?
Thanks.

"back spacing" is an old car term. The offset you need will be close to the stock offset (I'm not sure what it is). But you CANNOT talk about off-set without width of the rim. Whenever anybody says "what offset is that" they should include what width and offset, because you need to know both.