I downloaded demo yesterday mate, really liked it. Yeh it is a bit crap not being able to change graphics in game, you have to do it in the launcher before playing.
I found that turning motion blur off and AA at 2x, vsync off gives best results, the game was running maxed out at 100+ fps and was really nice, looks to have a great selection of tracks. Definitely worth a try if you fancy rally games, real rally games.