Phantom racer is another way of enjoying this hobby, and in fact, I'm working on a custom 350Z, too.
(Besides, the real 350Z racer is said to be available for customers next year, just like 911GT2)
The 2002 WRC cars have a common silver box on the roof, and that's a part of the GPS tracking system. I can generate a neat CG trace of each car.
Just when I'm thinking of buying a cheap navi, I realized that DVD/navi is getting obsolete, and Hard Drive navi can do a lot more.