OK, I'm warming to the idea of testing the Moons. I did a measurement with crushed aluminum foil behid the Moons and found that they are only .6" more into the airstream. I'm trying to find a way to mount them temporarily without drilling my wheels - for the time being.
I went out looking for a test course. Richmond is terrible with hills, but I think I found an essentially flat section I can use. I did a few experimental 70-50mph coastdown runs and I think the course will work ok. Perfectly flat would be better, but that just isn't available anywhere around here.
I do have one technical problem. How in blue blazes do I mark the end of the coastdown at 50 MPH? Remember, I'm going 50 so I can't just step out and put a chalk mark on the road