[jeff88]

Welcome to the site! Looks like you are well on your way to a great vehicle.

Some suggestions:

*Maybe extend the front air dam down in front of the tires for a tire spat effect. This might make your air dam more worthwhile.
*I would seal up the outer edges of your belly pan, so that the coroplast attaches to the bottom edge of the side panel/door. I fear that air is coming in from the side, which might cause some turbulence and maybe a parachute effect, effectively making the pan useless. Seal it up and you might see a better result. (Only a thought, you'll have to confirm.)
*Kammback. You might be able to use the spoiler mounts to do it as well, so you won't have to make holes or even need tape.
*I would definitely try the rear diffuser. You can even design it so it deflects air away from your hitch, so that the hitch becomes almost non-exisent, aerodynamically speaking. You could also just extend the belly pan all the way out to the point of the hitch.

I have no advice for turbulator tape, but do a search here, I think there are a couple of threads that talk about it.

Don't be surprised if you have to replace your starter sooner rather than later. All that EOCing will kill your starter.