I just did some measuring on my 2011 mustang gt I have 275/40/18x9 with a +35mm in the rear and the tires sit flush maybe +/- 3/16 I have pics to post but I'm new and it doesn't let me. I was wanting to buy 19x10.5 with a +30mm offset (I have rims, falken koblenz gunmetal with machined face, that aren't made anymore an I love them but they are getting old and used) so that's what I found on Craig's list. I did the online calculator and they will stick out 24mm more that's a full inch. No good!

Also how do I post pics