[aerohead]

Originally Posted by 19bonestock88

I figured I would restart this discussion, a member on here supplied me with some free individual vortex generators, and gave me a good idea to test the airflow without needing a chase car and photographer... He suggested to use flour sprinkled over the roof of the car and drive at low speed; there would be indicated attached flow where the flour was swept off, and that would show the point of separation, indicating to me where to place the vortex generators, giving the best possible result for the effort...

In addition to flour,NASA successfully used diatomacious earth for flow visualization.