You're wasting your time with any sim on the Dreamcast. If you want
good sims for a console, wait for Playstation2. It will bury the
Dreamcast same as the first Playstation buried the Sega Saturn.
Advanced, realistic driving simulators are found only on the PC. End of
story. This may change in the future, but that's the case now and in the
near future. I wouldn't hold out hope though.