Yeah. I want my parachute sealed in this case. Or, perhaps, not a parachute.
Made a few tweaks to the panel today, I think it's on the right track now.
Lowered the rear edge to better meet the spare tire well curvature, and added some precision coroplast:
Started on a set of small aluminum panels that will help seal off the front and side edges completely.
Also tweaked it around to bring it a bit higher off the ground. I'm now able to convince myself that this thing should be helping, but I'll have to get some FE results to feel better about it. Today's commute was inconclusive, but also not great.....