Finishing this today, I'm happy to publish this: https://steamcommunity.com/sharedfiles/filedetails/?id=1662222417
The car is funny to drive, the prefabs is ready-to-use but feel free to change the script variables to test it.
Drop the prefabs in the map, it uses the classical FPSPlayer from Leadwerks.
The car is based on joints: 4 wheels, 4 damper and 2 Hinges for the directions.
The script incorporates smoothing damping modifications to get the car stable; modifications on the velocity.
There is a funny speed boost system added.
Here is a little video test: