Has anyone played with the idea of putting on rear diffuser fins on their Roadster like the Lotus Elise / Exige? Any idea why Tesla didn't go that route? When I look at the rear of the Roadster something doesn't look functionally right and appears as if something is missing, I think this is it... It's suppose to help reduce drag which I think would be key for an EV. Might be a fun mod to do. My guess is that it channels air flow backwards and limits side to side channeling which covers a larger area and gives a higher drag coefficient. Also as the DiFlow video shows, extending it further from the rear line of the car keeps the sticky turbulent air away from the vertical rear plane. Just looked at the Model-S and it appears it has 4 fins on the rear diffuser which act as channels. Even the Nissan Leaf has one!!!