Above correct re caulk. Note when reinstalling skip the caulk on the bottom to allow any water intrusion to escape.
Here is a thread re mirror mounts and what I found and did to secure mine. Pics & more details included.
https://www.irv2.com/forums/f103/tig...ds-576514.html
I accessed the backside of the mount by digging out the foam underwood on pass side. Allowed me to thrubolt the fwd side mtg bolts using a piece of fiberglass as a solid backer drilled to accept longer bolts, washers, nuts.
Working with wrenches was by feel but not too difficult.
The rear attachment were self tapping screws that catch a structural tubing but I changed mine to larger threaded by tapping the same holes drilled out for the new tap size.
Used Great Suff foam to refill the foam removed and spray painted black.
MAJOR IMPROVEMENT AFTER ABOVE