considering rear turbulence management

[Philip1]

I currently have a brace of vortex generators on the back of my wagon. I haven't seen any change in my mean FE since adding them so I am thinking about an experimental deflector. It would be placed slightly behind the hatch seam and sit at about a 15* (from level) angle downwards. I am also planning to add some side skirt extenders that start at the pinch weld and flare out at the rear wheels( borrowing ideas from LMP cars of old).