Burros seem to be almost, but not exactly, like the Uhauls with a inner shell. I've found on our
Uhaul that the space between the inner and outer shells varies, some places there is a gap of a few inches, other places very little gap, so you have to be careful if you do drill any holes. A few things I attached in our
Uhaul I was able to get a piece of wood between the walls for reinforcement.
Uhaul used the plastic inserts in the fiberglass for attaching things like the cabinet hinges, curtain rods, and the marker
lights.