.cD
trying to parametrically model a car - from scratch - is incredibly hard (beyond the amount of time I'm willing to invest at the moment). Simplification won't yield much, if any, useful data considering the chaotic nature of this sort of system (small input changes yield great output changes).
But, I'm trying to come up with a way to reverse engineer large objects cheaply... I need to do more research, but right now the only solution I've got is building a large rotating platform and casting a laser line over the car and video recording it... Not practical at the moment as that platform would have to be motorized to move at a constant angular velocity (and cars are heavy
).
If I can find or come up with a way to reverse engineer large bodies on the cheap - this wouldn't be limited to a Jetta
For reference... here's an expensive method
Photogrammetry
you get....
in a .stl file -- techniques like this is how a full scale clay model is digitized for further analysis
EDIT:
As far as time is concerned.... Time to run tests is no problem... It's mostly a set it and forget it sort of thing. Well, maybe an hour or so of setup... It's just getting the model
Doing things like that NACA are no problem if I can get that foil shape parametrically... Something like a car, freaking hard
I'll have much more time this summer though