Great work! I will try the prototype on itch.io!
Some suggestions:
- Place a link to itch.io on you first post here.
- Place a video of the game in action, also in the first post.
Now some comments: you've said in your post about "Suspending a RigidBody" in the GTPlanet foruns, that you tried the rigid body + joints approach, but it was too unstable. I understand that, as this is my approach in my game, and I've solved the instability at high speeds using a higher physics FPS (I use 240 FPS in my game), and simple collision shapes, like cyllinders for the wheels, not custom meshes.
Anyway, I understand that having a simulation as a target, the joints solution might not be ideal.
Also, Godot physics seems to run more smooth in general when compared to Bullet, but I've not made the jump to Godot physics yet because I cant' set the position of the center of mass, and this is key in my game.
Other comment, about the spring arm solution: Juan just proposed a change for it. So, I don't know if it will change your solution, but I think it's important to keep an eye on it:
https://github.com/godotengine/godot-proposals/issues/2560
You may also want to keep an eye on this:
https://github.com/godotengine/godot/issues/45333
All in all, it's great to see a project directed at racing and vehicle simulation in Godot! I think everyone will benefit of different approaches coming from different projects!