I think on a cargo van or a vehicle that's obviously a work truck it's fine to have a roof vent. A roof vent on a travel van or motorhome is more acceptable, because I think most people figure the reason you bought it is to sleep in it. I used to have a roof vent on my old 1991 Ford Econoline back in the 1990s. It was a plain white cargo van with no rear or side windows in the cargo area. On that van, I think it looked OK to have a roof vent because it was a work van. Would have looked even better if I had a roof rack or a ladder on top, or lettering on the sides. Plus, it was never parked overnight with the lid open, and especially not in a public area. Glad I don't have it anymore. That "white cargo van" syndrome thing wasn't as big of a deal back then either!<br><br>Now I have a window passenger van, my blue 2005 Chevy Astro. Part of the reason I really like it, is because it doesn't look like they type of vehicle you would suspect someone is sleeping in. It's got factory tinted windows, but I'm getting them tinted even darker for privacy. And for good measure, I'll put up blackout curtains over the windows and a tall curtain behind the front seats to separate the front from the back. That would be the only giveaway that someone might be living in the van. Otherwise it just looks like an old soccer mom's minivan or family hauler. Of course, many people, especially law enforcement, know people live and sleep in their vans, and they might be more wise to this than the general public. I think if I were to put on a roof vent on my otherwise very stealthy looking minivan, it might tip off more people that I'm sleeping in it.<br><br>That really frustrates me, because I know how beneficial a roof vent is. A compromise might be parking so that one side of the van, or the rear doors are very close to a fence or bushes (where nobody would walk between the van and whatever you're parked next to). I open one of my pop-out windows (with a screen on the inside of the van, attached with velcro or magnets to prevent bugs from getting it). And then aim a quiet household or 12V fan (table-top or clip on style) towards the open window. Or, aim it the other way to draw air inside. Easier and cheaper than having an extractor fan venting into a hole in the floor, although that's also an idea I've considered.