the holes are for another pleated panel that covers the center of the roof . hides the screws .
radiant barrier for metal building is a good insulation. same as other stuff sold for cars. just. marketed different .
the truck has lizard skin under the insulation.
The outside of my shop under the steel is wrapped in Prodex. Good insulation. Used to have a party once a year and would wrap the keg in Prodex with a little ice. The next day the ice would be still there.