The camaro vents are just about exactly what I am looking at doing. Ive got access to a pair of fenders I think I will be testing my ideas out on. I continued to research and there don't seem to be any production fenders floating around so I may use the fenders to make a mold and create some vented fiberglass fenders that resemble the camaro vents. Who knows, if all goes well and the final product turns out nice I may see if they catch some attention in the market.
By the way Nelsonian, I like the two scoop vents you have mocked up on your z. Never considered that but they match the hood surprisingly well!