I've noticed that there are numerous threads regarding wheels, offsets, and tire sizes. It would be good to collect all of the info on what we know works, what modifications are required, in one thread with a sticky.
To start with - my stock wheels, 255/40R18 rubber, 10mm spacers, work with no rubbing when the front fenders are rolled. If the rears were rolled as well, I think 12mm, possibly even 15mm spacers, could work.
So whatever the stock offset is (anyone? anyone?), we know that we can add (subtract, technically) 10mm to that, with 18x8.5 wheels.
It would be great to have a chart of sorts, so that we can look up sizes and then choose wheels accordingly.