I think we're going with something along the lines of #5, first image posted.

Of course I'll likely wind up doing another 2 or 3 pages of variations, but we've got the basic idea down now.

This vehicle works as a personal transport, but also works in unison with other parts. The modular design incorporated by future-man allows this to join with a flying apparatus to become like a plane, seamlessly attach to a trailer for hauling of supplies, bus people around in larger transportation attachments, etc. The wheel in the back (there are only 3 wheels) goes into the body, like a plane's landing gear. I think sketches of the attachments will make this concept make more sense to those who don't get it with words.