We usually use "tadpole" to describe three wheeled vehicles with a single wheel in back.
Did you tuft the boat tail to make sure it works? As a former boat tail owner, I have a hard time believing a tail that long (even if just on the top and without wheel skirts) wouldn't show.
Hucho would suggest an approximately 3 degree angle on the diffuser [for a liftback body style] and it looks like you're pretty close (it's hard to tell in the photos). Good craftsmanship, too!
Oh, and I like your front end work. Looks very industrial!
