hey guys Aerohead has the best explaination IMO. Turbulent boundary layers are on the scale of 10x the skin friction of laminar boundary layers but stay attached longer due to more momentum close to the surface... There is a critical Reynolds number that estimates when the flow trips from laminar to turbulent naturally. I believe this number is roughly 4 million for a flate plate. I wouldn't be surprised to see turbulent flow from the hood back. Boundary layers are very thin. I would try producing a thick turbulent layer before any adverse pressure gradients.
I borrowed this image from a google search of CFD car:
I can see where the vortices may form coming around the front windshield with sharp pressure difference in the column and side window.
Check out the Cp. Very interesting. I need to find the thread I was arguing about the stagnation point on the front of cars
