Jamie writes:

A typical
car can probably idle for 8 hours on a gallon of gas.

A car consumes more like 1 gallon/hour idling.

but it sure
doesn't take that long for someone to kill themself that way!

Only in Hollywood. It's not a "big nod" like in the movies.

CO emissions from cars are typically near zero. The CO2 will displace air
and suffocate you. But neither is particularly fast, and survival
instincts are hard to countermand.