You are misreading the data. Modern cars put out a typical 100PPM, but can reach up to 1000PPM when cold started (e.g. catalytic converter not warmed up).

Now a charcoal grill - that will get you 3500PPM easy!

Not misreading, mistyping. I should have said "up to 1,000"
Still plenty to kill you. And that is with a perfectly running car with zero leaks or other issues.
But, like you said, a grill, water heater, furnace, etc can put out even more and kill you faster.
The point I am making is that there is still plenty of CO coming out of a car even with cats in place. It still kills many people a year and will continue to as long as they are dumb enough to run their car inside.

I'll echo the common sentiment, AC works great unless I'm at a dead-stop, facing the sun in the Houston summer.

I'd like to focus on the other part of the question though - are you running with the AC off in an attempt to save gas iow with the windows down, or just trying to cool the cabin via vent air?

Because the windows down is less efficient than running the AC and keeping the car buttoned up.

Thanks, I'm aware of that. I'm a motorcycle rider. I like the natural air, as long as it's not 90º+.

Right on! :)