There you go, that’s one thing…provide a hole at the top of the heat pile…the window cracking option could be one but it is not fail safe. Maybe the top of the roof is open all the time unless the ignition is on. That way if all power fails, there would be air flow through the interior.
Next human detection. That’s nice, but if the roof was solar panels, it could power up a good sized fan. With 100W for example, I was able to power a car radiator fan and that’s like a house extractor fan.