I have this exact problem on my driver rear, front SF mount.
The nut inside the body just spins, and I can't get the bolt to properly tighten.
What I did is, I drilled a small hole (10mm) in from the side, and was able to get enough on it to tighten the bolt enough for only 1/4" gap between SF and body.
Now my goal is to drill the hole out a little larger and get the nut tacked welded to the body, so I can tighten the bolt properly.
Isn't this a pathetic way to design a mount?
If you're gonna make something totaly inaccessable wouldnt ya wanna make sure it'll never break?!?
