Think of a 2nd gen V and a G8 as basically interchangeable. I'm aware of only 1 guy who ran a 3rd gen V wheel on a V2. There was a fair amount of work needed to allow them to work. For that reason I don't think they would work without a great deal of work on a G8. Unless you can test fit, I would pass.
The offsets are pretty aggressive for the stock g8 fenders. Will minimally need a roll, maybe even need to trim fender liner, pull fenders and add camber.
2009 Liquid Red GT
Currently Enjoying : WeatherTech Floor Liners, Tein S. Tech Springs, Monroe PPV Shocks/Struts, SuperPro Polyelast Top Mounts, 19" Sport Wheels & Firehawk Indy 500 Tires, 18" GT Wheels & Continental DWS06 Tires, Subwoofer Wire Mod, Kayhan Audio Headunit, 35% Llumar Ceramic Tint, Morimoto 35W HID Kit
Soon to come: CTS-V 4 Piston Brembos, CTS-V2 Sedan Wheels