So sorry about your car burning... and at Christmas, too. wow
This is something to really consider... protecting documents.
Always looking for cheaper options, I looked here:
http://en.wikipedia.org/wiki/List_of_fire-retardant_materials
Fireproof, waterproof... but what if your van was stolen...???
If you have ever had documents stolen... well, it's a nightmare.
And, your stash shouldn't really look like "your stash."
IMO - anyone stealing a camper will be looking for "your stash."
Someone once gave me the advice to photocopy all my documents and to leave the originals where they will be completely safe. For non-replaceable documents, you should always have a "certified copy" made at the source of the document, which will have a notary stamp and be as acceptable as any original.
There are places in cars and trucks that are hollow metal, which may get heat, but will not allow enough air to combust, especially if something is wrapped in insulating material and in a metal tube. If the camper is stolen, it would be so indescreet that it might never be seen... to be used to steal your identity. If you don't have a hollow metal place, you could make one by cutting into a panel... away from things that serve as fuel for fire.
Interesting subject, alrighty.
To add:
Photocopy all documents, credit cards (both sides), and credit card contact numbers for all cards.
Also: If there was a way to block the wheels from moving while you are parked, so that even if someone hotwired it... it wouldn't drive away... I'd figure that one out, too. (rocks?? noisemakers?? metal bar into the rims???)