This is from their FAQ
What about ventilation?
This is important for comfort, and we've provided for many options. Our display model has four "mushroom" vents, one at each corner. These can be opened while at rest for passive cross-ventilation, even in the rain. We also fitted a roof hatch with an integral 12-volt fan, which will exhaust a lot of air. The hatch can be opened a few inches while raining, at least if it's not raining sideways. In addition, we've fitted two small 12-volt fans on the interior for air circulation. It's hard to arrange for much more ventilation than that. Yes, it'd be muggy inside on a hot, rainy August night in Louisiana. But so would ANYTHING without air-conditioning on a hot, rainy August night in Louisiana...
One option for really hot weather is to carry an inexpensive 10x10 pop-up tent with screened sides. This could be set up over the 6'x8' Teardrop Camper in minutes, allowing you to sleep with the big side doors open, and access the galley out of the rain.
Both prototypes were given a foam-backed liner on the interior to eliminate the annoyance of interior condensation. Looks nice, too.
I'm starting to sound like a marketing guy for these people. I am impressed with the design generally, until we get some examples in use, can't tell how well it can work, but I feel it is suitable for at least some of us.
Incidentally, anyone know where I can get some of those mushroom vents?