My CF5s 20x11 with 53 offset and 315/35/20 pilot SS fit flush with fender with my Steeda sport springs. Actually these tires are 1" taller than stock on my CS and bring my speedo in line with GPS readings as factory speedo settings tend to be less than actual speed. With the width of the speedo needle, it's really hard to tell your actual speed. I suggest you check your speedo with a GPS first. With my car loaded (trunk and seat delete area) I can get a very minor rub on the inner lip when hitting a bump.
You will need an adjustable ph bar to centre your rear axle,as the gap on both sides will be different by 3/8" or so and it bugged me until I did it.
With Whiteline rear sway bar and end links, you can fit a 12" wheel on the rear with 335 tires
The taller tires and 1 1/2 drop from the springs gives the car an awesome look.