Nice pictures everyone. I need to learn how to do that. Finally a question I can answer from direct, but old, experience. We found that ALL the stuff INSIDE the box had to be secured as well as the two (2) front doors.
What we learned (the hard way!) is that EVERYTHING inside needed to be secured inside a "containment" container like eggs and all the other packaged stuff everyone has, then padded together using clean towels and clothes.
The two outside doors were eventually secured by several strips of velcro attached to glued portions. Cheap, easy and quick. And yeah, we had to reinforce the entire reefer to the floor as some Interstate holes were DEEP!!