Ouch that demo is hard! I think I've read somewhere that the physics are set to a "pro" mode on this demo, presumably the full game will have the pro and not so pro modes to choose from to make it more playable, like there was in the prologue game.
Def makes it tricky to get a smooth lap in without a whole load of practice...which to be honest I can't be bothered with on a 1 track time trial demo....there are better things to do...like dirt 2, or mw2
Still can't wait for the full game though...reckon/hoping it'll be awesome!