Why is it dangerous to sleep in the car in the garage with the gas on?

Yes, the gas engine will release a bad gas in the exhaust pipe. Then the garage will be full of that then it comes in to the car, taking over the air. Finally, you suffocate then die.

Otherwise, if your car is sealed so no air will come it, the air will run out, and you die.

The exhaust fumes contain poisonous carbon monoxide. Continuous inhalation of this can kill you. You will not wake up.

Yeah, there is no where for the poisonous gases coming outta the tail pipe to go, so you breathe them in, and they kill you. Not good :(

from carbon monoxide poisoning from the exhaust of the car.

The exhaust contains carbon monoxide. It is a gas which has a higher tendency than oxygen to decompose into your red blood cells. You will die from suffocation by inhaling it within half a minute. Your skin will turn brightly pink/ red after inhaling carbon monoxide.

carbon monoxide the silent killer cant smell it or see it