I haven't read through all the posts here, so this may have been asked already, but here goes :
How do you intend to make this car legal ?
What are the laws like when it come to creating your own car without the government mandated crash testing etc.
How will you test out the safety features of the car such as how it will react in a crash ?
if I wanted to create a boxfish car, I would simply modify an existing car such as a metro to stay legal by modifying the body like Dave Cloud did.
I can imagine actually creating a car that actually looks like exactly like a boxfish.
Aquarium shops would be beating down your door for add space on the car.
I have seen a few 'art cars' that resemble all sorts of crazy things ( and they stay legal somehow )
( Something like this - but with a car underneath and a windshield / windows )
I love your enthusiasm on this project. And by the way, the rendering on the images is superb ! Was radiosity used ?