Look into the Axiom Streamliner Road DLX rear rack. It's made specifically for road bikes that don't have braze-ons or eyelets for rack mounting. The bottom of the rack connects to a bracket that mounts on on the skewer of the wheel and the top mounts using the bolt for the rear caliper. My desciption might not sound so hot but it's a pretty decent rack for what it's for. The top is slimmer so as to bring your panniers closer to the cent of gravity. Because of the slimmer rack top, it's definitely a pannier rack. Give it a look as I can't think of anything else that will work without modification.

I'm not too keen on CF bikes but you'd need P-clamps to maount most ay other rack and as others have mentions, it'll probably do some damage to CF seat-stays.