17x8.5 on the front, with a 40 offset and 245/40/17 tyres
18x9.5 on the rear, with a 38 offset and 265/35/18 tyres.

Jimlabs spreadsheet says so, but what about rubbing on full lock? does anyone have any pictures of cars with larger rear rims than fronts?

 

That should fit without any serious issues. Try searching for the "larger rear" in this section, I know someone here was running 17/18 and had posted pics.

 

so, anyone have pics of cars with larger rear wheels?