Steve, the one you post the pix of may be faster around a racetrack, but the Mine's car looks MUCH cleaner for street use.
Having the radiator at the back is likely to create a large area of HIGH pressure under the bootlid, which is where you really want LOW pressure, so you'd need much more wing to compensate for the lift it would produce.
Unless they are putting the rad in a tunnel.....but I can't tell from the pix
Any idea what ballpark price would be for Mine's car in the video ??