Currently, all Raydium cars are using a sphere system for wheels ("sphere cars"). This way to handle the physics provides a realistic feeling (suspensions, inertia for front wheels rotations, ...).
I'm now trying to create a way more arcade driving style, and replacing sphere wheels by rays is supposed to allow this ("ray cars"). I've just added a new file to the SVN, raycar.c, with this new system. You must press the "e" key to start simulation.
The car body is always the same (the good old clio.tri box), but I launch 4 short rays from the wheel positions and create contacts between the ground and the car if rays collides with the ground. These contact points are quiet complex, trying to emulate suspension and real tire behavior ! This is done using separate properties for the transversal axis of the tire (second axis in ODE contact points). This setup allows A LOT of tuning.
The car is currently able to move forward and backward, to turn left and right, the suspension is able to absorb huge chocks without making the car boucing. The next step is to make the car stable (it flips very easily) and making it turning ... better