My original design on the first day failed to be aerodynamic enough to satisfy. I originally thought the design would be streamline because of the curvature of the shape and it would allow for applied downforce however, I didn't think about how the downforce would create extra drag.
My second design proved to be far superior aerodynamically due to its reduced size and the smaller frontal surface area. The idea of ball bearings adds the extra challenge of 3d printing a custom axle for the ball bearing to fit on. The rear wheels may be covered because, upon researching, I have seen cars that cover their rear wheels to reduce drag.