Picked one up from 1800radiators. The have great prices. Cost was just under 170.00. Local pick up as well. The only hiccup was they gave me a 2009.5 radiator. Fits the same except holds more pressure and my old cap did not fit. Had buy a new one with a 20 psi rating.
2009 G8 GT (FAST4DR) SRM 20% Tint, spyder fronts and tails, 8000K HID headlights and fogs, Borla Cat Back, 1/4 mile 13.57 @ G8 Gone 2013 stock tires. Since added Vararam CAI, 93 octane vararam Cortex tune, SLP longtubes, high flow cats, Mustang dyno 341 rwhp and 351 torque. Suspension: Tein Springs, PPV (2011 Police) shocks and struts, Super Pro: radius rods, spring seats, Blue Polylast front strut mounts. Mevotech lower control arms, BMR: cradle inserts, trailing arms, and toe rods.