Aerohead, I can't post images ( using my Android phone ) , but I have a picture of the " shelf" just behind my rear taillights.
Both the oil drip test and the paint test showed flow in the same direction as later tuft testing confirmed, but in other areas, the direction of the fluid was completely off.
I placed the drip on top of the Kammback in a depressed area where a bolt was.
As I got up to speed, the air blew it out of the depression, but gravity seemed to overcome it more than the force of the wind.
I know in the past we have spoke about something to use for creating smoke for aero testing.
This is just an observation, but after seeing kids vaping and the HUGE clouds of highly visible smoke coming from just a simple puff, I can't help but wonder if something could be created to use the same stuff they use in these things.
I come up with some pretty absurd ideas sometimes.