Hi Vojtech, I've tried the Godot VehicleBody and VehicleWheel nodes, and they actually work well, but for the behaviour I am looking for, it was just not enough. I'm using 6DOF joints for the wheels behaviour, and everything is just a regular rigid body. I've talked about some aspects of the game in the Godot Forums:
https://godotforums.org/discussion/22177/racing-game-trackmaster-free-for-all-motorsport/p1.
Feel free to ask me more, here, or in the forums!