I have 2 Honda 2000's [with parallel kit wired to a "Shore - Genny" switch] in the front generator compartment. I did use a thin sheet of non combustable material on top of 4 4x4 blocks to raise the exhaust's over the lower ledge of the hatch which if left open provides enough air for the gennys to run and also keeps the compartment from getting hot - the door just hangs down vertically. I will ,and suggest you think about, putting fuel in containers that just fills an empty tank. It's kinda hard to see into the tank when filling with a gas can and I always just let em run dry anyway. I'll just take off the top and dump it in - no overfill / spill problem. If I think CO might be a problem I'll mount a small 120 V fan up high in the compartment & plug it in but it seems sealed off from the living area.
I don't want to leave the gennys in the truck - 1. they'll get swiped 2. DW will take off in the truck with the cord attached.
3. they take up too much room in my SB w/slider hitch.
Thats just what I've done and why - good luck.