3/8" spacer in the front for sure. my car is an 06 and i dunno if that matters with the size of the caliper or whatnot. IMHO i dont think it would work without the spacer. Longer wheel studs are an optional thing, but I didnt feel safe with the amount of "bite" i was getting on the stock wheel studs. Not enough threads for safety. As far as the rears I am not running any spacers at all and not having any issues with clearing the calipers in the rear. The stock lug nuts and studs work fine on the rear. Im not going to lie, the pics will be awhile as the car is in storage over an hour away from where I live. I mounted the tires and wheels on the car last night and stood there and looked at it for about a half an hour and its perfect in my opinion. The "buldge" of the tire sticks out of the wheel well slightly, however the center section of the tire is well within the wheel well. I went with the 28x11.50-15 ET Streets bc I had great success with them on my stock Bullitt wheels in the 26x11.50-17 (1.5 60fts). Like I said, my car is lowered as well and I dont forsee any issues with rubbing. If I do, then I'll worry about it then, and Ill probably have a smile on my face bc the car pulled the front wheels or something hahaha. Wait nevermind, Im N/A. Also, in order for the black 06 that posted to have not used spacers, he had to do some serious grinding. Im talking SERIOUS. There is no way you could get the fronts on without a spacer without grinding....ALOT. spacers in front, rears no spacer. I listed the PERFECT tire sizes in my earlier post. Order exactly what I did and I promise you that you wont be disappointed. I also plan to drive these wheels and tires to and from the track. Hope this helps!