Ok... so I wanted to look up info on IF powder coating the OEM rims would degrade the metal, possibly causing a weakness in the rim itself. Am I right to assume that the OEM rims are new for 2011 and have not been used on any other Toyota car?

Any idea where to contact or locate info on the type of alloy used for our wheels?

I've found one really good discussion on powder coating which, although not finding any solid yes or no answers, is a great read:

http://www.eng-tips.com/viewthread.cfm?qid=151053&page=10

I'm about 98% settled on wanting to rock my rims with the OEM Super White, as my long term plans are to get a 2-tone paintjob on the tC (SW on top with a dark blue at the body line) and I think the white rims would pop.

most likely they are aluminum. nothing different than any other rim.