That image was posted by me using the admin account.
Of course the wheels in your model have nothing to do with the actual location of the tire ray cast, so make sure that is inside the physics body of the chassis.
You posted another video showing vehicles with very high spring constants, causing them to jump all over. Those spring values are very important and vary based on mass and spring length. Adjust those values until you get something that is loose enough to not jump around, but tight enough to hold the chassis up.
Beyond that, I suggest posting a demo so we can see the behavior for ourselves.