The Nissan 350Z came in quite a few configurations: Base, Enthusiast, Gran Touring, NISMO, Touring and Track (not to mention Coupe or Convertible in several of these configurations.
The Base, Enthusiast, and Touring models came with a 225/45-18 Front tire and 245/45-18 rear tire. In 2003, these were quite unique sizes and there weren't many tire options available. Tire Rack now has 35 different tire models from brands like BFGoodrich, Bridgestone, Continental, Dunlop, General, Goodyear, Hankook, Kumho, Michelin, Pirelli, Sumitomo and Yokohama.
Click here to view the best selling 350Z tires in the above tire sizes.
The Gran Touring Coupe, NISMO and Track versions came with a 245/40-18 front tire and 265/35-19 rear tire. There are currently 9 tire models available from 5 different tire brands with matching tires in these sizes.
You can see the best selling 350Z tires in these sizes here.
The options for 350Z tires have really opened up over time allowing for a selection with varying price points and tires with different performance characteristics.