I would hope so, but the reason I raise the issue is that my encounter with CO came from use of a miner's carbide lamp in a partially enclosed space with a volume about that of a typical automobile. The flame on the carbide would have had a length equivalent to one or two typical candles. The result was a raging headache which dissipated upon exposure to fresh air.

I checked for some public health information about carbon monoxide on Wikipedia. The estimate is that about 40,000 people seek medical attention for CO poisoning annually in the US. Over a ten year period (1979-88) there were 30,244 unintentional fatal cases of CO poisoning, as well as 25,889 suicides. The article mentioned that catalytic converters scrub about 99% of the CO from car exhaust, although an engine running in an enclosed space can still cause problems. Far fewer people use car exhaust as a means of suicide because of this.

end of rant - stepping down from soapbox.