Quake III Rally is a mod for Quake III Arena that turns it into a fully fledged racing game, with racing modes, deathmatch modes, capture the flag, demolition derby and more.
Updates in this release include real improvements in the physics model, a less punishing damage system, a less annoying "Wrong Way!" message, fixes for a whole host of bugs, improved joystick/keyboard control mode, working observer cams and more. As always see the documentation for a full rundown on changes and all the options you can change.
This version also includes temporary sounds, but engine noise is off by default because of problems getting the Q3A engine to loop it properly. You can find the cvar to switch the engine sounds on in the Documentation.
There is a known problem where sometimes the game doesn"t end when a race finishes, you can currently get around this by going into spectator mode. This will be fixed in the next update.