Am I correct in thinking that since a design patent protects ornamental design, then if a design is necessary for functional reasons, the design patent doesn't

Am I correct in thinking that since a design patent protects ornamental design, then if a design is necessary for functional reasons, the design patent doesn't protect it? That you couldn't design patent a wheel looking like a circle, because that is a necessary part of its utility? Because the filed complaint itself seems to admit that the protected fuselage shape is necessary to achieve the ~0.37 drag coefficient that both vehicles have, which it also admits is necessary to attain appropriate range on EVs of this class.