I wanted to do a boat tail, but it would have to be like 80" to come to a full point, I had the idea to make it collapsible! something like one of those old fashioned "travel cups" that telescope out from the base.
Like this:
Prius Tv with Tom Bell
The tag and "alternate directionals / reverse light / brake lights will go in the tip section which will be clear, the "stock color" will be faux carbon fiber.
It will add about 15" to the car in total length retracted, so it will be easy to get around town and park etc, and once on the highway, flip a switch and a combination of air venting in from a movable vent and a telescopic mast (like an old power antennae) will deploy it to its full length.
Flip the switch the other way and it gets "reeled in" shouldn't take more then 15 seconds either direction.
I am seriously shooting for a kit that can take the Prius C to 100mpg at 65mph, with no mechanical mods, re-chipping or lowering.