[ttoyoda]

ebacherville,
What do you envision for the top view of the tail? Do you see it coming to a point in the top view? Or just getting narrower?

Compare these two extreme designs : The m111 and the aptera.

The m111 had only one job. To go around a track. To do this, the drag had to be low, and the car had to be stable at high speeds, thus the tail fin on the back, I am sure that is not just for decoration. For an object to be stable, the center of MASS must be ahead of the center of DRAG. Thats why an arrow is stable.. The heavy head is in front, the tail feather which make drag are at the back. Try to throw an arrow backwards, it will turn around. So the m111: It is close to the ground, and a half teardrop.

The aptera has many jobs: Letting the driver see over minivans and SUVs. Allowing overweight aging yuppies to get in and out without getting a slipped disk in their back. Having a place to put the turn signals and brake lights. So aptera decided to make their vehicle way up off the road surface, on those front cessna landing gear wheels, and that giant tail-plane underneath for the rear wheel. The back of the tail was left wide for the turn signals. With the aptera up off the ground, making it a full teardrop shape made sense.

The crx is never (well, probably never) going to be up 2 feet off the ground. And it is going to have 4 wheels, not 3. So the m111 design is the one that can be most easily copied, even though their engine was in the back, and yours is in the front.

If you make your tail go down to the ground, you might worry about it scraping. But if you let it be flexible or hinged at the car, with spring preload pulling it down, (like a clamshell idea) and have a caster or two under the back (which normally does not touch the ground) then you will not damage the tail when you go up a ramp.