Licensing is an extremely complicated process, and as Mista X said, EA seems to have the Porsche license (remember Need for Speed: Porsche Unleashed?). Anyway, I think it's pretty astonishing that Sony/Polyphany/Whoever did it was able to get so many licenses. They did find a nifty way around the Porsche holdback, though, with the RUF cars.
Maybe the success of GT3 will make manufacturers more willing to license their cars to the series in the future. I think there are even a couple who attribute the success of some models to this game (I saw something like that with Suburu's WRX). I also think it'd be nice to see more from both Porsche and BMW, as those companies have a HUGE presence on the real GT circuits.
By the way, has anyone else noticed that the Viper seems to get licensed in just about everything? Maybe that's part of their strategy; they certainly seem to have plenty of die-hard Viper fans.
