aerohead may have something to say next time he checks in, but meanwhile...
At the location you indicate, in that era, they would have used a deep V-shape. Later Tatra and others found a 3-piece windshield with narrow 'wind-wings' incorporated in the sides beneficial. Probably because a flat, vertical windshield is best optically, and safety trumps aerodynamics. Eventually you get the late-50s GM Wraparound windshield that had a lot of distortion.
Actually, an aerodynamic fore-roof truncated to a flat plate sounds a lot like my VW Beetle.
