My apologies Hotnuts, was reading your comment, then Rex's query and put the two tgether.
Actually, if you'd studied examples of bridge trusses and treated the front and rear axles as the bridge anchors, without seeing a side elevation of the car , it looks to me like a proper Pratt truss configuration.
Bridges are occaisionally aerodynamic as Tacoma Narrows demonstrated. It was fine last time I went over it, though.
Rest assured these guys don't need to lie awake nights worring about the diagonals directions.