It would seem odd that as Elon has his experience with SpaceX in the background, and SpaceX engineers are consulting for Tesla, that the metal construction was

It would seem odd that as Elon has his experience with SpaceX in the background, and SpaceX engineers are consulting for Tesla, that the metal construction was done overly clumsy without a reason. Equally likely is, that they had a clear plan when designing the metal work on the Model 3 - but it is not obvious to people trained in the way the automobile industry works, as Tesla certainly is thinking differently.