DannyGT (if I didn't butcher his username, sorry if I did!) is running 19x9.5/10.5 +22 all around on 275/305 tires.
My take on this is that we can run a lot more aggressive sizes than this. Then again, it depends on what you're willing to do to get to that point and what you're using your car for. A lot of wheel sizes fit, it just depends on if you're willing to do a mild tire stretch, or add a lot of negative camber. It also depends on your ride height as well. I mean, even in the Civic world (I know that world is definitely taboo on here
) the stock sizes were 17x7 +45, but my friends and I have been able to successfully run 18x9 +29 so it's all in the minor details.
I hope that made sense. I'm still waiting on my suspension setup to do some measurements to see where I can push the boundaries.