I'd worry that the cat can jump out. Then again, transparent backpacks apparently get hot and stuffy. I wonder if a non-transparent backpack with a plastic window and ventilation slits could work (or just with a grille instead of the window).

There are various backpacks with transparent plastic observation domes, which I think are included in 'too little air'. I'm guessing a grille dome would work better.

Edit: maybe something like this:

[–] Zorcron@lemmy.zip 2 points 2 weeks ago

I have a backpack similar to the second one with mesh windows on the front, top, and small side windows and it’s great. No breaking out, and great airflow when it’s warmer.

[–] Alcoholicorn@mander.xyz -1 points 2 weeks ago (2 children)

It looks like the hole is too small for the car to get out.

[–] AltheaHunter@lemmy.blahaj.zone 1 points 2 weeks ago

cats are liquid

[–] SlurpingPus@lemmy.world 0 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

Cats are known to fit basically where their head can get through.

[–] Alcoholicorn@mander.xyz 0 points 2 weeks ago

We can test this.

Try cutting a hole the size of your cat's head minus fur in a box, then reinforce with ducttape. Then wave a toy outside the hole. They will quite enjoy swatting things through it, but fail to actually get through.