Do the tires for a 350Z fit 2003 G35 6MT?

no.. the 350z came out wtih 3 differnet types of rims when it was released in 2003. Gotta specificy. not to mention hte g35 game out wtih 2 different types in 2003 as well

sorrry didnt read 6mt part, still 350z had 3 different types of rims offered.

yeah the wheels are either 18 or 17 inch

Simple question, simple answer. In '03, all G35 6MTs came with 18" rims. If the "Z" has 18" wheels, then the answer is Yes They Do. This applys to both the Track Rays, and the Cast 18" wheels.

Lou