Strangely enough, I installed 3 of my panels with SS sheet metal screws and Goop, and the other 3 with well nuts and stainless steel screws. I have seen no difference in stability or holding power as they are all 1/2 inch from the roof and very little air passes under them that would create lift. Enough air to help cool them is good.
I'm not sure what is right and what's wrong, just what works and they are all still there and solid. I have to clean seagull poop off them now and then, so they get checked frequently. Living on an island has it's drawbacks. lol
2013 Silverado 2500 HD Duramax/Allison Tuned
Aviator Wright Flyer #1919
"First In, Last Out". 11B4Y
DAV, MOPH, VFW, 5/7 Cav,1/8 Cav Assoc.
11th ABN Pathfinder Co. N7MIP