You actually can use your own cars in "two player battle" On the top it says 1 and 2 which stands for memory card 1 and 2. Just go there and it will display whatever cars are on that memory card.
One big thing that makes me mad is how they took away the full screen replay in two player battle. I had loads of fun racing my friends and competing for the replay at the end (replay focused on #1 position) but they took this feature away and the replay is split screen which looks retarded
And like neanderthal said, I'm sure not having Ferrari and Porsche is a licensing issue. Yeah, it would be cool to have those cars but isn't a major downfall of the game. And RUF makes up for Porsche.
GT5 will most likely have online (they better) and I've heard they might even have damage......
