Rather than cutting into the roof to install a fan, has anyone removed the back window panels in a cargo van and installed a louvered window device to provide for increased airflow? Ideally, the louvered window would have a baffle system, that can open and close? From the inside of the van, a fan would provide for airflow. If there is not an aftermarket window(s) available, perhaps it is possible to craft something that can be removed, with mosquito netting or substitute, for overnight stealth camping. Comments?

 

Having the rear windows open does almost nothing for airflow, as the vacuum behind the van pulls air up against it. Real airflow comes from an opening on the roof or sides....
Maybe a pop out side window would be best....
....for camping you can get those small 12 volt fans, and hook them up to an rv battery. Those roof mounted vents with a fan built in are great, but then you are cutting.....

 

If you pull the plastic trim pieces just above the rear lights you will see a vent there. Older vans appear to have them on both sides, my 2015 has it only on the passenger side. Perhaps you could duct a fan output to these?

I found mine because... I... spray foamed all the cavities and I actually put so much foam in it expanded and came out the outside of the van! I now have no vents, which is funny... because I was thinking that top channel in the frame/body looked like a suitable rough vent for something and it is! My doors still close fine so I am not completely upset. These vans must have more than just the one vent for air, no? Is there anything up front?

Anyways please keep the ideas coming because personally I think I screwed up the flow of cabin air in my van, from the front heating/cooling vents through the cargo hold and out the back. I'm looking for ideas too.