If you have an inexpensive dash camera that you could temporarily mount on your roof, you could easily set up a series of cloth strips to indicate roof turbulence. I used to do this with a few airplanes that I owned. In your case I would basically just take a strip of cloth, about 12" long, and tape it to the roof in various locations. Tape only the end near the front of the coach. With the dash cam running, you drive the coach and you can see the air turbulence by the way the cloth strips move. Not very scientific but if you see a few strips dancing all around, you know that you have some serious winds. If they all just lie flat, or trail straight back, things are fine. If the strips lift and seem to act like they are trying to take off, that is an indication that you have an uplift situation and you may have to make sure that your panels are fastened securely to keep them in place. Have fun. :B
