possible to run 18s on a sport?
 

I know that most people want to go to bigger rims, but here the roads are not great and the extra sidewall might be nice. Plus 18" street and track rubber is much cheaper.

dont see why not

Not too many 18's fit over the stock brakes. If you want some nice looking ones, go here:

http://www.the370z.com/tires-wheels/...orgestars.html

the base 18's that come stock without the sport package also fit over the brakes. I believe those are all that we have confirmed as of right now.