For what it’s worth, I got mine from this guy on Ebay:
http://www.ebay.com/usr/lugnutkingiv2005
You just need to measure the distance between the cap screws to make sure you pick the early or late size. I think the early ones are 2 1/8” and the late versions are 2 ¼” What got me interested in the first place were these spinners offered by American Racing, but at $500 a set I lost interest real quick:
