The fact that the fasteners inside this little marvel of engineering are tough to get to and are usually jammed tight as concrete isn’t news here, I’m sure.
In the OTS, access to the underside of this box is limited by the side curtain box. You cannot get there from here.
I have a new box to install and about the only thing I can come up with is to cut out part of the inner fender (and replace it of course). Talk me out of it.