I'm running RX-8 wheels on my car, which have an offset similar to that of fwd cars. Mounted with adapters that add 1" spacing all around.
The wheels are 18x8 and the tires I run are 225/45-18. I'm also probably about 2" lower on the springs I have.
The only rubbing I get are from my mud flaps at full lock on the steering. Otherwise no rubbing at all.
Stock G6 wheels get up to 18x7 and run 225/50-18 tires.
Being on stock suspension you should have absolutely no problems wanting to run 18x8 with 235/45-18
More spacing in the back will put you closer to the quarter panel, but not being lowered it likely won't get too close.
I come close, but the wheel cambers in pretty aggressively the lower the ride height gets so it clears the quarter panel and inner fender liner without issue.
If you can find wheels with the right offset, or a staggered set of wheels that would be better than using spacers to get the look you want.
I ended up going with adapters to fit 5x114 wheels for a wider range of choices, and then threw another oem set on heh.
I couldn't find much with our 5x110 bolt pattern, but maybe you'll find something you like.
Last edited by CruisinG6; 05-12-2018 at 03:58 PM.