I used Subaru Rally Car 99, upgrade the turbo and install the NOS (my favor equipment in rally). When you are in the race, best to jump out infront of him at very beginning, because it's impossible to drive behind AI car. But of course you have to be know the track itself. And sometimes wallriding helps whne comes to sharp turns (remember tail hits wall, no penilaty)
i used the RS200 just with NOS, found using bost just gave me too much lag and when i changed the gearing so it's always on boost i would be constantly spining the wheels not getting anywhere..