I bet those subs beat like hell, what amp are you powering them with? I have the 400.1 kicker amp myself, it goes hard!
maybe tint the windows darker, the tails, get some overlays for the badges, door handlers. I really like those subs and box!
2008 G6 Gxp Street Edition
Mods:Interior LED Neon Lighting, Debadged, 20% Tint, Flowmaster 40 Series Exhaust, Res delete, Alteza black housing taillights, Spyder black housing headlights, CRAB O3 CAI, Airraid Throttle Body Spacer, Racingline Strut bar, 91 OCT WAMS Tune.
Audio:400.1 Kicker amp, 12" Kicker CVR Ported Box