Chris Lewis writes:

"Near zero" CO emissions from cars can kill you if you're not
ventilating well enough. Starting a car in a closed garage and
sitting in the car to read a book is about the easiest and gentlest
ways to die there is.

Bunk. The pCO2 respiratory stimulation will kick in long before integrated
pCO is enough to affect anything. Car exhaust is nearly pure CO2 and
steam, plus very tiny amounts of things like CO. As a suicide method, it's
absolutely stupid, because the mostly likely outcome is a brain-damaged but
still-alive subject.

The dose makes the poison. Your swell ideas about what happens given a
lethal dose of CO doesn't mean inhaling car exhaust will administer a
lethal dose. Citing unusual cases where it has happened is to commit the
fallacy of selection.