[Bearleener]

diesel_john, what does your stepped tail look like? How is it fastened/reinforced? Thanks!

Has anyone thought about a retractable Kammback? Sure would be nice if it would fold together at low speeds, reducing vehicle length for easier parking and making it slightly more street-legal.

One possibility would be, say, 3 panels that fold out at the top and sides, perhaps deployed with a pull string arrangement through eyelets at the corners.

Or how about a clear plastic, inflatable, conical bag (something like those temporary bouys used for sailboat regattas), which would roll up into a little box when parked? Maybe you could even use the low-pressure area back there at speed to inflate it. Or exhaust gases at the tailpipe: pump directly to inflate, use a venturi with side tap to create vacuum to deflate.