A/C window fogging and defoster

[kiyakubuke]

Originally Posted by particlewave

While redirecting as much airflow as possible through the vents and footwell may work, it's only a band-aid.

As kiyakubuke said, the problem is that the flaps that divert airflow are missing foam and letting air through where it's not supposed to be.
The real solution is to pull every last flap and replace the foam with something that won't deteriorate. Not an easy job

just found this post. going to check this weekend.
Interior vent debris