Check the sticker on the inside drivers door, should tell you there. I think it's right around 34-35 psi. I've read of people running them as high as 40 for better fuel economy but that's sure to wear down the center fast.
EDIT: Just checked. The Track package comes with the PZero (not nero) 255/40/ZR19's, which the sticker says should be 35 cold. Not sure if that's the same tire that the Brembo cars come with or not.
Black 2013 GT Premium | Track Package | Recaros | GT500's | JBA H-Pipe | Borla Over-Axles | OEM GT500 Spoiler | Koni Yellows | Steeda CAI/Tune | Steeda Ultralite Springs | Steeda Adjustable UCA/PHB | Steeda Billet LCAs | MGW | Forgestar F14's