2008 GXP. Where to start?

[IR II IP IDEATH]

aww no one reppin the flowmaster(sad face here) i got single chamber flowmasters on mine and i couldnt be happier with it, i also have the knn intake and i think its worth it mainly for sound and gas mileage.....oh and for my exaust it only cost me $250 installed for 2 mufflers and res delete.
YouTube - grand prix gxp drive by
couple other vids too. have fun with you GXP you should love it(mine is 08 as well)

[blk ls4]

i went with a cold air inductions cold air intake looks real nice and sounds good it was 266+shipping 2006 Grand Prix GXP Intake [501-0520] - $265.95 :: Cold Air Inductions - Cold Air Inductions Inc - Air Intakes