I'm installing e39 sport package wheels (17X8, 17X9) on my e28 and it appears the only clearance problem is with the spring perch in the front, so I'm guessing I need about a 5mm to maybe 8mm spacer. I also want to try to use the centering rings (for centering e39 wheels on the hub of older cars) and wonder if they'll be compatable with the small spacers. Any comments, suggestions, or ideas? Does the Tirerack sell spacers? If not, where can I find some? Thanks for any help.