I'm looking at a set of 17x8 wheels w/ the 5 on 4.75" bolt pattern. The offset is +29.5mm.

Working out the math (www.skulte.com) I get about 5.4" of
backspacing.
4" Centerline + 29.5mm / 24.5 + .25" lip = 5.41"

The max BS on the front is 5" and rear is 5.875" for third gen's.

Again, doing the match, I would need ~ 1/2" adapters on the front and no adapters on the rear.

The question is do I really need a 1/2" adapter? Will I run into rubbing issues if I don't? Should I just go with a 1.25" adapter on the fronts since I can't find anything thinner? If this is the case, I'm better off buying a different set already set-up with the correct BS.

 

Most wheels with around a 30mm offset are 5 on 120mm bolt pattern for BMW's - Close to our 5on 4.75" (120.6mm), but not exact. Double check with the folks selling the wheels. If you run wheels with much more than 5" backspace up front, it might contact the strut or the tie rod end (unless you're going with a huge diameter like 19's or 20's). We can machine bolt on billet adapters down to 3/4" thick, but the lugnuts and studs will poke past the front slightly, so you'll need cavity back rims (pockets on backside in between the drilled holes). If it's just barely rubbing, a thin slip on spacer may do the trick.