It's a good shout Djay but it's still quite a primitive engine compared to what's around now. But at the time it moved the driving sim arena on in big leaps and bounds. Once the modders got hold of it as well I think I hit the heady heights of around 18fps and upped the AI to a level that wasn't completely pathetic as with was standard.
Got to say GP3 and GP4 have really stood the test of time. Every bit as enjoyable as some modern day sims.