I know Stillen has 18x8.5 on one of there cars, with 245s, but not sure what offset they use. I am trying to find out if this will rub or not on my car?

17x8 with 245s Momo Arrows didn't rub on my 2000 Auto.

 

Well, let me try to guess for you: i have 18x8s with 235/40/s and i think a 41 or 39 off set, so ur 37 will push it even further out which is very good!! plus the .5" wider wheels and 245s which is going to look good and almost flush with the fenders. From a looks stand point i can almost guranntee they will look awesome, because i wish my sticked out more, but u have to test-fit them for sure just in case. check out my pic.