Clean Air makes no sense (stop mimicking me, BTW)

So Ferris, Cameron and Sloane chat in the garage for a long time very comfortably.

You probably already know what the problem is.

Let's think about the scene in 'Office Space', where the older guy tries to commit a suicide by letting his car run in the garage, where he has no ventilation. This seems to be some kind of actual method that should, in theory, work.

Suicide by fumes - by, let's make this clear - letting the car run and produce exhaust fumes.

Where are the exhaust fumes from the Ferrari in the garage? There is only one door, so in essence, the fumes should've been accumulating pretty fast until the time to check if the trick worked. The garage should basically be full of noxous gas that's dangerous and very uncomfortable to breathe (cars like that are usually much noisier than 'shown' (played?) in the movie, their 'talk' should be done by shouting, if not twisting, but we'll let that slide).

This engine has basically run in the garage with only one open door for a long time - that door would NOT be efficient enough to properly ventilate it to a breathable level, let alone a level that wouldn't cause eyes to water, coughing and general discomfort and awful smell when you are breathing. There is NO way these people could carry on this conversation so casually without coughing and hacking and eventually wanting to just be outside - heck, they might even faint.

Where are the fumes?

That the garage air is THIS CLEAN, no fumes in sight, no breathing difficulties, conversations can be had casually, and even small workout being possible just MAKES NO SENSE.

If you doubt me, just try it. Try it for yourself, and do it honestly. Put your car (doesn't have to be a Ferrari) in a carage of similar size and let it run there for a similar amount of time (that has to be estimated, but make your best, honest guess) and tell me if it was possible to spend ANY extended amount of time in the garage without any kind of protection from exhaustion fumes, let alone carry casual conversations there.

Not to mention that we should at least SEE visible fumes at some point, because it would have become thicker, as it can't dissipate very wll in that garage, but the air looks perfectly clean.

Now, it IS possible that the garage has some super ventilation system, but Cameron's dad doesn't sound like the kind of guy that would think to install such, especially since HE NEVER DRIVES the car, so he never has to experience exhaust fumes in the garage, so therefore, why would he even THINK of such things? Perhaps the garage came with the house with powerful ventilation stuff pre-installed, but shouldn't we at least hear a small hum (besides the car engine running) in the background to denote this?

No matter how I think of this, it just makes no sense.