boattail mod in flow illustrator
 

After many, many, many trial runs in flow illustrator, I have this:

Stock form
Attachment 12801

Modded
Attachment 12802

I will keep trying to improve it and make it shorter. I will also try my truck and see what I can come up with. Let me know what you think.

think
 

My apprehension lies with the program being limited to 2-D flow.
Automobiles are bluff bodies in 3-D flow.
I went back and looked at the Japanese Society of Automotive Engineer's paper on the HONDA Dream solar racer.
They used a couple of preliminary programs,one being a turbulence model,to prep the input for the full Navier-Stokes Equation.
The car was reduced to 85,000 wire-frame elements to generate the pressure and drag data.
This is the most sophisticated mathematics I know of.The program is solving an equation of 85,000 variables simultaneously.
When Hucho was at Volkswagen,they would wind tunnel test a model to experience it's wake.After they knew something about the wake,the wake itself was added to became part of the wire-frame CAD model of the car,of which would go back into the CFD program.
I feel that Flow Illustrator is just not powerful enough from which to derive useful data.
Even with massive parallel super-computers,the auto makers must still take full-scale models into the wind tunnel to realize final forms after all the CFD is completed.