In Dann's o-review video review of Scar, he describes the temple lugs as x-metal. I double-checked that with some other sources once upon a time and got a different answer, they weren't x-metal, but, even though the sources were trustworthy the statements couldn't be backed. So I consider that one an open question.
And of course Plates have no metal at all; I'm assuming that was a joke like the Frogskins...
The official description of the Scar (which can also be found in the 2001 Oakley Annual Report):
Fusing separate sculptural forms into a single unified piece, The Oakley Scar Sunglasses combine injection-molded durable X Metal with lightweight O Matter frame material. A mechanical cam achieves optimal positioning of the earstems, whether folded or open and changeable moisture-wicking Unobtainium nosebombs ensure a snug, secure fit.
There is only one part of the Scar that is metal.....