To directly answer the question you asked in the title:

ICE vehicles and animals consume oxygen and produce CO2. Plants produce oxygen and consume CO2. Your car's exhaust is poisonous to the animals in your garage, not to the plants. The plants love your car.

The problems with atmospheric CO2 have nothing to do with biological effects. The problem with atmospheric CO2 is its effect on solar insolation.

I wouldn't use this analogy in an argument with someone who does not understand anthropogenic climate change.

This is a bad argument. Your conclusion happens to be factual, but it doesn't follow from the premises.

Being in an enclosed space with an internal combustion engine will kill you because of the CO buildup, and no, that doesn't happen in the open air. CO does oxidise to CO2 eventually, so it doesn't just keep building up in the atmosphere.

The main harm caused by burning fossil fuels is the CO2, which is wreaking havoc on the climate and will kill billions - but not by poisoning them.

People struggle to think on a global scale and if you don't understand how the atmosphere insulates, "that's inside and this is outside" is a convincing enough argument for a lot of folk. Throw on the fact that some of the most powerful institutions in the world have very strong interests in keeping ICEs going and it's pretty easy to see why so many people still believe those myths

If it is common knowledge that shutting a garage door with a running ICE vehicle inside will kill you, why do you think so many people think 1 billion ICE vehicles aren't bad in the atmosphere?

The problem with having a running ICE vehicle in an enclosed space is that you reduce the oxygen levels in that space and your vehicle then starts rapidly dumping carbon monoxide out the tailpipe, which is dangerous to humans at much lower levels than carbon dioxide exposure.

This isn't related to the issue we have with carbon dioxide emissions producing global warming.

We aren't going to reduce global oxygen levels far enough that vehicles dumping carbon monoxide out their tailpipes and asphyxiating people becomes an issue.

It is also common knowledge that taking a bath with a running lamp will kill you, why do you think that has absolutely no impact in people's buying lamps?

A car running in a small enclosed space is very different from a car running in the open in the same way that a lamp running underwater is very different from a lamp running in air.

That being said I do believe we should strive to have personal vehicles and public transportation be converted to EVs as soon as possible, because the issues with running ICEs vehicles in the open (which are different from running them indoors)

Because most people are completely scientifically illiterate and do not understand the analogy you're making because they don't know what "atmosphere" is.

I had a friend who went down the right wing rabbit hole and he said that the earth is so big we can't affect the environment that way.

Blew my mind. Trump supporter now as well.

I'm not here to diss EVs or praise ICE vehicles, but I want to simply directly answer your question. There's one simple mantra that is applicable to a lot of things in life...the dose makes the poison. Not odd to see people extrapolate to that your scenario.

In one, although the quantity is greater, you're "diluting" the gas into the humongous atmosphere. In the other, you're taking the gas straight up undiluted.

People mostly believe whatever is in their interest to believe. No one's beliefs are 100% internally consistent.

A lot of it has to do with propaganda, both the oil and car industry have successfully convinced people that they need petroleum and a car

What they think is no mystery - they think the atmosphere and ecosystem are vast enough to absorb it. As "proof" they'll point out things like smog in Victorian London being much worse than modern Los Angeles. They can't produce any numbers or science but they find these mental images convincing enough.

I like to think most people, at least where I live, know cars burn up the planet. Problem is most can't afford a $50k AUD EV, even on finance, but a 2011 Hyundai shit box or a 2005 Toyota hilux is less than $10k.

Oh also, cars are being made to be replaced within a few years. Cost and build quality of modern vehicles pushes me away from buying an EV. Hopefully in the future, they become more ubiquitous, cheaper, and we can solve the problem of handling old batteries and stability.

It's not the people don't think cars are bad for the environment. It's that people consider the nebulous cost to be worth the short-term benefit of actually being able to get places.

In theory, concentration and expose time could mean that whatever is hurting you in an enclosed garage isn't a problem outside. Which is some what true. Carbon monoxide bonding to the hemoglobin in your blood cells is what kills you in the first scenario. The CO2 levels take a lot longer to rise to dangerous levels and there's plenty of warning to leave the area before fixation becomes an issue and it's still not the same issue as climate change.

In reality, it's propaganda. But if you want to argue with people, don't use the enclosed space as an example. Batteries can also offgas and quite frankly, I wouldn't store some of those cheaper EVs in a garage or at least, an attached garage.

Both are primarily a means for profit, as most tasks accomplished with a car are more reasonably done a different way. The efficiency of road based motorised transport is so abysmal that it almost doesn't make sense.

The only reason we rely on it currently to such an extend is because our entire economy is highly irrational, except if seen from a supremely privileged point of view.

What's a "butt tire"?