A freely available racing game down-loadable through the Steam Store, this game is fun to play, has highly modifiable tracks including loops big jumps as well as big crashes (although no damages).  However, connecting up with friends has been problematic at best.  Racing against other is more parallel play than since while you can see the other players, and can race with them, there isn't direct interaction with the other players (each racer is immaterial so nobody can touch the other racers).

This game is fun, but difficult to get everyone connected together on the same server, so unless we can get the bugs worked out, or worked around, it's a potential game rather than a current game.