Coastdown testing shows a slight reduction in speed, but that's also due to the fact it's getting quite cold out.
The airflow definitely reattaches onto the spoiler, and I noticed that the naturally occuring counter-rotating vorticies off the sedan shape become apparent. I was driving without VGs after realizing they're useless in crosswinds and noticed similar patterns in the dew even without them, but further down.
With the vortex generators positioned like \\\\\///// (as opposed to the standard
/////\\\\\), there were two high-pressure zones present at the base of the rear window:
Code:
Cabin
___________
/|\ /|\
Decklid
(The /|\ lines show the directions of flow.)
I noticed the same spreading high-pressure pattern start about 5 inches before the edge of the decklid (at the beginning of the spoiler).
I was thinking about taking the side pieces of my partial kamm and putting those on to give the air off the sides a vertical surface to detach from, hopefully stopping the vortex generation.