The shape I'm using is what most of the other streamline templates on this forum have used. It originates from aerohead's photo album called "perfect streamlined shape". I haven't used the simpler "clock face" shape which is very close.
Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - aerohead's Album: Book illustrations - Picture
I'm sure the exact shape, give or take a degree is just nit picking. These shapes are basic guidelines for those that haven't studied aerodynamics. My one semester of Fluid Mechanic only gets me a little dangerous.
I cropped your image and scaled it keeping perfect proportions to the template I'm using. I think your scale might be just a bit off.
