His reasoning was that in many places such as state or provincial or federal or national parks, you would be turned away if you were running a propane tank inside the van that wasn't set up to be filled from outside of the van (i.e., access hole & door to the propane locker from outside). As much as I didn't like the idea of hanging a propane tank on the back of my van, between the exorbitant cost of hanging a tank under the van, and the nasty thought of cutting an access hatch through my van and propane locker, I've pretty much decided for Plan A.