This is what I got done. I ran out of time and didn't do the air dam. (Anyways I need to get a ramp at the end of my driveway.)
Sorry this doesn't have much to do with my thread topic. This is just the temporary fix until I decide what is optimal.
Before, pipe insulation lower grill block, no upper grill block:
After, clear acrylic upper grill block, coroplast partial lower grill block (you'd think the best location for air intake is center-bottom):
I ran out of black paint and was dismayed by how bad the dark gray coroplast looked. Surprisingly, my wife tolerated it, at least temporarily.
I hope this car will make an interesting build thread if I dig into it this winter.