Will 275/35-18's fit?
 

Will they fit in the rear without modification? My car is not lowered, but will they fit if my car was lowered? Thanks!

I don't see why not, assuming your wheels are wide enough. My tires are 265/35/18 on 9.5 inch wide wheels.

I just want to make sure there will not be any rubbing issues with the plastic inner fender lining.

Howie, no prob on the 275's it's all about the offset, you'll want a 9"-10" wide wheel, offset should be in the neighborhood of 48 if you can find it, but you can go more towards 42 if need be, 5x114.3 bolt pattern in case you need to know. I have 265-35-18 like Max, but he's got an inch on me in the width (the WHEELS I mean Max, not the plumbing). I'm obsessed with weight, and my rims were about 4lbs more each for the 10" width, plus they had to be custom built and shipped from Italy, so I went with the 8.5's all around. Max, you have the L-Sportline rims, right? Very nice, love a staggered setup, works great on these cars. Howie, if you're willing to do a little 'massaging' you can go all the way out to a 315 in the rear, but offset is critical at that fitment.

I already have rims. Just haven't put them on. I got Volk GT-N's. 18x8 offset +37 and 18x9 offset +38. Am I going to have problems with the 275 at this offset?

Volk makes very nice wheels. my problem at the moment is since my re-tune I can't get traction if I start off more than about 1/2 throttle, and it's making 0-60 timing hard to do. I need a good traction tire.. I miss my Bridgestone RE730s.. those had the best grip I've had so far.. these Michelin Pilot Sports are just a name tire, not much else.
Howard: you're probably going to want to ask for recommendations on tire width based on the wheel width, and go with what the tire shop suggests. Your wheels are slightly thinner than mine, and I don't know if trying to run even wider tires is a good idea.

275's are perfectly fine on nines, but Max is right, with a 38 offset, you should make sure, I usually call DAZZ for fitment questions, they have good guys there, or call Precision Installations, they know their sh#t. Those Volk GT-N's are very nice, gonna look great on the SC. Max, half throttle? That is definitely a problem, let's see what happens when we bolt my Hoosiers up to that bad boy........

ooooooo
those should look mighty purrty