The vent system for the battery gases in the Porsche was not set up correctly, so instead of venting to the outside, they were venting inside. It was not a factory issue, but a replacement battery issue. Whoever replaced the battery used an incorrect battery and did not install it properly.
My brother’s 2015 Jeep has the battery under the passenger seat, but it is properly vented to the outside.
So those of you who have a battery inside your car, make sure it is the correct battery and if it requires venting, the the vent system is connected and working.
I had my mobile back in the day.
The battery was behind the passenger seat.
The rusted out floorboards guaranteed plenty of ventilation.