Rather than deliberately trying to build a concealed compartment somewhere which could be misconstrued as an illegal compartment if you're ever stopped and the vehicle is extensively searched, maybe a better way of thinking is to figure out what normal compartments would be best for stashing the camera in.
If I'm away from the vehicle (out of sight of it) for any length of time it usually means I'm sightseeing and the camera is with me.
If I'm away from the vehicle because I'm shopping then the van is parked in a parking lot where there are other people around and the doors are locked. I'm only gone for the time it takes to do shopping in one store before I go back to unload. Risk is minimal and I simply toss my camera in a closet, close the door and the laptop travels under my pillows on the bed anyways. They are out of sight and out of mind.
The actual chances of the van being broken in to and the thieves having enough time to thoroughly go through the van are marginal at best. Not something I spend a lot of time and effort worrying about.
The only time I have ever had a break in in my van was when it was parked at my mothers' apartment building in the visitors section (way out back) overnight. 3 other vehicles were also broken in to that night so it wasn't that my van was targeted. They didn't search the vehicle, simply grabbed what they could from the drivers' seat and left. This was during the period that I wasn't van dwelling and my mother lived in a larger city that today, I would never spend any time in.
Oh and at the laundromat, the van is usually parked within sight of those big windows all the laundromats seem to have....heck I sometimes don't eve lock the van then....