[FiatLuxDave]

I see the ultimate solution to be a way of making cars not be hot when parked. I live in Florida, and the first 10 minutes of every car ride is the AC trying to get rid of the residual heat from being parked. I would happily spend $5000 more on a car that was not a hot-box when parked. There is no law of physics that says that the car interior must be sealed when the occupant leaves the car.

There are third-party solutions like https://www.walmart.com/ip/Solar-Powered-Car-Vent-Window-Fan... , but this is just a workaround for the fact that the typical car is not properly vented for a warm climate while parked. I understand that there are theft concerns with more venting, and that for cars in cold climates you would rather the car hold its heat while parked. Nevertheless, I think that car companies could solve this problem easily by having extra vents which would open when the car was put in park to keep the car interior at around the same temperature as the outside air.

[godot]

Interestingly I have recently purchased one of those third-party solutions (not the one you linked, one that is supposedly an even stronger fan), and these have pretty minimal effect. It helps a little bit, that's about it.

I think it's not as simple as just having more venting. When I lived in Sacramento a popular method is to leave a 0.5-1 inch gap on all the windows while parked. It actually helps quite a bit (hot air exits near the top end of the car interior), but when the car is under the sun for long enough, at best the temperature in the car may be 100F (instead of 120-140F with all windows rolled up), which is still enough to be a killer. In those sorts of temperatures I think you actually need an AC system running for it to have a real effect.

[FiatLuxDave]

Yes, those little solar fans are pretty ineffective. Cracking the windows helps but is not as good as rolling them all down. I don't know of any cases of a child dying in a car with windows rolled down but I suppose it is possible. It is mainly children being left in sealed cars which results in fatalities.

I was thinking more like venting which was designed to use the temperature difference to pull air through the car, like the designs used in desert vernacular architecture. Maybe something like a miniature Persian windcatcher, or a vent in the roof and floor which open when the car is parked to allow convection through the interior. But really anything to make the car less like a sealed hotbox.

[Sophi13]

I totally feel you on the first 10 mins thing haha. I usually stand out with all doors open, ac on full for like 5 minutes before I even get in. It's a problem almost everywhere and can't wait to have an effective solution to that. Someone in this thread shared that tesla doesn't let the car heat up to higher than 100 degrees, hopefully other car manufacturers take note.