they should only keep the best of the the old tracks.
Also, didnt polyphony say they had trouble fitting all the game on a single DVD?? then how could they add more tracks, for their second game, they enhance graphics even further! you get more polygon data, more texture data... but you still get one DVD! surely they couldn\'t have you put in a DVD choose a car, change the disc, choose a track and race! and then when the race would be over, put in the car DVD again!
People say that GT2 is a good example of a multi disc racing game, but I disagree! GT2 basically uses the two disc to separate arcade and sim mode, but both disc have relatively the same cars and tracks on them, just with a modified physics engine!