[R] = Hide / Show Rays
[P] = Pause / Unpause game
[F] = Fullscreen
Basic steering / obstacle avoidance / wandering AI (using a Raycast field of view) + extra influences on the car (steering towards waypoints, away from other cars, etc.)
This still has some problems, namely that cars can get stuck if they end up in a part of the track from which they can't see their next waypoint (solving this would require constant detection of which Waypoint Zone each car is in, which would be quite expensive)
Simpler version: