Sega GT is not a sim, nor is it anything near as good as GT3 in physics or graphics. For content, RFactor is the way to go, for simply the best physics available the live For speed, it only has a couple of real cars, the rest are all fictional. There's quite a few mods for RFactor where you can download road cars like VW Golf GTi's, Honda S2000's and Ferrari F430's ect.