No spacers needed on Beemer rims if you choose them right!
Try BMW 3 Series (E46) wheels for the front and 5 Series wheels for the back.
Check offset on
SyTyArchives offset calculator.
Stay within 5 to 10mm + for the wheels to stick out,
don't go wider than 8.5" or 9" wheel with for the front and
something between 8.5" and 13" in the back and you're fine.
Offset changes 6mm for every 0.5 Inch in wheel with change.
PS: Also some wheel packages for the X5 work straight away
(front and back that is, with no spacers req.)
They stick out 9mm in the front and 15mm in the back.
To compare the old Turbine Style ZR-1's in 17x11 without
spacers stick out exactly the same(15mm offset 36).
"Daytona Race" in 20x9 Offset 45 and 20x10.5 Offset 30
from Rial is such a package.
Blown' :turn-l: