Yeah, you can also do a WAMS tune, lowering springs or coilovers, front strut bar, grounding kit, MMI's and headers, headers are up to you, I have them, I like them but can't say if they are totally worth it or not, but there only $300. All in all man the G6 is decent, your going to have the power steering problem, but that's covered under recall, as long as you have gotten your recalls you shouldn't have too many problems. The pano is great, sometimes messes up with the settings, but fixes it's self however when my 6 was my families my dad knocked the knob in the winter and it messed up so much that we needed to replace it cause it wasn't closing right. I don't know if anybody else has but just don't try opening in winter aha! Body kits are straight forward most like the AIT, all kits will for on all G6's! Then you are left with custom mods if you want to, LED rear tail light, anything paint, new engine dampener, etc... If you look over on the other forum I have a progression that I have done pretty much everything for this car - the brembo brakes, including tho some custom projects. Lampoon also has a 05 GT and a progression on this forum and the other and is really knowledgable if you can get a hold of him
and cruisin has some cool stuff too, but is kicking a 09 with a 2.4 so not the exact same but still can help with typical G6 probs, lastly GMManof3 got a AIT front bumper and ik was working on the rest so he might be able to help with body kit questions as far as installation. I mention these guys cause ik there on somewhat often! I hope this helps my man and if you have any more questions I am busy but don't mind them sent my way and I'll try to respond ASAP!