body.addShape VS body({ shape: ... })

[eric-t-a]

I have a RaycastVehicle positioned at the origin. Then I tried to create a floor.
If I do it like this it works fine:

const groundBody = new CANNON.Body();
groundBody.addShape(new CANNON.Plane());

groundBody.quaternion.setFromAxisAngle(
    new CANNON.Vec3(-1, 0, 0),
    Math.PI * 0.5
);

but if I do it like the below, seems like the floor does not get rotated and my car get's stuck at the origin cause there seem to be a wall that did not get rotated to be the floor.

const groundBody = new CANNON.Body({
   shape: new CANNON.Plane()
});

groundBody.quaternion.setFromAxisAngle(
    new CANNON.Vec3(-1, 0, 0),
    Math.PI * 0.5
);

Am I doing something wrong? Docs aren't very descriptive so I don't know why there's two ways to do the same thing (if they do indeed the same thing)