No i sure haven't. The 20x11 fit my 315's perfect. Plus at decent angles I get some rubbing. So i need to get the bump stops cut off. Is there a reason you would go with wider wheels.
I have the same wheels on my 08 GT500. I got 20x10.5 deep concave in the back with 315's. Have you thought about going any wider on your 20x11's? Do you know how wide you could go?