​RE: Mounting a Fiamma
My 10' Fiamma has been mounted without the bolts to the body of the van for
well over 10 years.  And 100,000 miles.  I used two mounting brackets for
many years but added a third about three years ago.  And have had no
problems with not having the brackets bolted to the body.  BUT I have
thought about doing that even though the three bracket setup is solid.  YMMV