The wheels in the attachment were sprayed with Plasti-Dip. It can be puchased at Home Depot. Looks like a powder coated wheel when done for a heck of a lot leass money. If it becomes nicked up you can simply peel it off and redo it. One note of caution..... Do not coat where the lug nuts seat. This is a compressionable material and as such can cause a torqued nut to loosen up. Mask the nut area before spraying or cut and peel it off (which the owner of the shown wheel was going to do. Also do not coat the back of the wheel. If your wheel should crack for some reason it can't be seen thru the coating. By not coating the back of the wheel you have someplace to inspect it. This appears to be a new fad with miata autocrossers and I thought I'd share it.
http://forum.miata.net/vb/showthread.php?t=439955
http://forum.miata.net/vb/showthread.php?t=439955