Ya I'm 150% sure the rx8 wheels rub in the rear without rolling the fenders. (With the stock rx8 tires).
I've confirmed it in person, and many CA members with the wheels have confirmed it as well. Its just ever so slightly. You could actually get away without even a full roll, just a slight tuck. (Though I'd do a full roll anyway).
Remember when it comes to wheels/tires, always look for the single person that says it rubs. Even if you see 100 people saying it doesn't...if one guy says it does, it usually means it will. There seems to be some sort of disease with wheels/tires with people being a bit...obvlious to whether they rub or not. I think it has something to do with the monatary investment in the setup. People spend alot of money on wheels, they don't want to be told that they bought the wrong setup. So they kinda of go all mental blank on the whole issue.
The image I posted early of the obvious tire damage...that was from a 6club member that posted that his combo didn't rub....=/
I have 17x8 +48 with 225/45/17 and I had to roll.