If you want to keep from denting the body of your van from the inside, skin your walls with thin plywood.
This way, if you toss a tool, a heavy part, or a tool box onto a shelf it won't contact the metal wall of your van and dent it or push it out.
What else can you do with plywood walls skins?
- Keep it plain or paint it to increase color contrast so it's easier to see things.
- Mount hangers, hooks, or lightweight racks to it.
- Run wiring behind it to keep wires clean.