Ok, let me know if this is feasable. I want to go with 18x10 in the rear and 18x8 in the front with 295's rear and 265's front. Do you think these will fit without rubbing? I heard they fit the 2004 GT so I would assume (I know it makes an hiney out of u and me) they would fit the 2005.
If I choose a tire that after being mounted to the rim is very close to the stock tire height do you think there would be any issues with the speedo being off a little?

 

I'm going with 255's and 18's all around. They look great IMO.

 

Probably not a problem, especially for the rear. If you keep close to the stock wheel+tire diameter, you'll be fine. Boomer showed us some results using different tire/wheel combos and most were < 1.5% difference in tire radius. Not a big deal since you probably don't read your speedo that accurately anyway.

Boomer, got those numbers?

 

That's where I'm at as well. Maybe 275's all around. I have to see if the tires stick out in the front.

How is it driving a car with 275's up front? Follow all the groves in the road? How much worse than stock is it?