Ebay is a listing service, not a manufacturer - post a link to what you're looking at buying.
http://www.bmwtips.com/tipsntricks/W...acer_notes.htm
Based on my experience, I would stay the FUCK away from anything made inexpensively as they are inferior in quality. I ran into heat dissipation issues, where the Z32 brakes & calipers were over-heating because there wasnt sufficient heat transfer going from the hub to the wheel. The wheel acts as a heatsink to help dissipate heat.
Anyway, when I did run spacers.. I dealt solely with Fred over at
www.wheeladapter.com - great quality, fair price, and absolutely knowledgeable. There are other brands obviously, but Fred is the BOMB.
Mike / ClearCorners.Com