We haven't had hot enough temps to even run our Maxxair. We get ventilation at night with the Maxxair cover open and we haven't had rain come in, and then the front window, under the open window guard, open about half an inch. Of course we had temps in the 40's at night and were running the heater.
For the day, we open all the windows
and with the jealousy windows
we haven't had any rain inside, but also have not had a real downpour.
So I think if it is hot, that all the windows open and the fan on max would bring in the most air. We have had the TV and Homelet out in the sun. Inside the TV it was HOT, but inside Homelet, it was barely warm. The tinted windows, insulation, and light
color of Homelet really resist heat gain.
Leaving the door window open on an unattended trailer would allow someone to easily enter by reaching in through the window and opening the door.
I don't understand why you wouldn't open all your windows. Are you talking about settings while you are inside sleeping at night? Then I would crack all the windows slightly open except the door. If it is day and you are inside or nearby, just open them all up. I wouldn't run the fan unless I were present.