What pads are you using? I'm using the stock CTS-V ones and they are ridiculously dusty but work amazing. I'm guessing yours are ceramic?
2008 G8 GT
Show:20% tint(50% Windshield), Gunmetal VMR V710's w/Bridgestone RE-11's Front:245/40R19 Rear: 285/35R19, GXP Diffuser, DDM 35W 6K HID's, Holden V8 Badges
Go: Vararam CAI, Kooks 1 3/4(no cats), Corsa Exhaust, Spartan Performance Tune
Brakes/Suspension: 6pot CTSV Brembos, Pedders GSR Struts/Shocks on HD Springs, BMR Front/Rear Sway Bars w/endlinks, BMR Subframe Connectors and Tunnel Brace, BMR Total Suspension Bushing Kit (Front, Rear, Rear Cradle)