Yeah Doug its all of that. I can buy the distances if the bottle was up in the bus I am having a problem with it stored down in the luggage compartment there was no vent above this compartment and could the compartment be air tight enough to fill and then come through the floor but how does that much gas get up in the bus its a puzzle. Lets try going at it from another angle do you think if someone poured enough gas in this bus could it get the windows that far away if not then its got to be the Propane then?