Old cars gassed people with carbon monoxide. Odorless and deadly.
Modern cars make basically none of that. Instead, you'll die of too much CO2.
Luckily, humans are pretty good at detecting gradually increasing levels of CO2 - it's what happens when 5 people are in a car together and someone says "it's getting stuffy in here, turn the vent on!".
Sudden CO2 increases can still kill. But gradual ones like a car gradually producing more and more CO2 likely wouldn't. Even in your sleep, you will wake up and find the air stuffy (it can happen when lots of cave people are all sleeping in a badly ventilated cave, so we evolved to handle it).
However, you shouldn't rely on the above for the safety of people - all it takes is someone to be drunk or taking sleeping pills, and they might not be able to act on their senses... Also, cars where the emissions system has been tampered with or faulty can still produce a lot of deadly carbon monoxide.
The last go-around about the keyless ignitions was kicked off by a 2017 toyota. The story was from 2019
https://www.nytimes.com/2019/06/28/business/keyless-carbon-m...