Couple claim they almost suffocated in their car due to airtight door seals - bullshit or not?

[KosherDill]

A couple are claiming they almost suffocated in their new car after being in it through the night, because of something about cars ''being more tightly sealed these days with their airtight designs''. They had to stay in hospital for a few days afterward. The car was not running, so carbon monoxide was not a factor in this, and the car was parked in a garage, and it was night time, so heat was not a factor either. The door locks malfunctioned causing them to stay in the car overnight. They made a group warning people not to sleep in modern cars because there is a danger of suffocation. By the time they were found, the wife was unconscious, and the husband was having difficulty breathing. Medics said if they spent just another thirty minutes in the car, they would've both died from oxygen deprivation.

Their dashboard vents were still there. Would tighter door seals significantly affect the passive ventilation in a car? Or does most of the air freely coming into the car get through the HVAC vents so tighter seals wouldn't really affect the amount of passive air exchange? (The ducts are always open if the vents are set to open, even if the fan isn't blowing.)

The studies I tried to find all seem to involve the Air Exchange Rates for vehicles with the intake set to 'Recirculate', which closes off the vents. For newer cars which don't have notched vent baffles, the Air Exchange Rate can be as low as 0.1 Air Changes Per hour. I can't find any studies on Air Exchange Rates for parked vehicles with the vents set to fresh air.

Or do the vents automatically close when the vehicle is parked/off? In this case the vehicle wasn't running.

Edited February 13, 2022 by KosherDill