Because the defrost vents seem to run all the time,
a dirty cabin filter will spray that dust onto the glass as it is brought in from the outside.
Not exact matches
That stink was coming from a
dirty cabin air
filter.
A
dirty cabin air
filter restricts the air flow around the evaporator core (the cold part of the A / C system) reducing its effectiveness.
Sure, a
dirty cabin air
filter can adversely impact your Toyota's heater and air conditioning system, but the biggest impact is on your comfort and well being.
It could be a
dirty or clogged
cabin air
filter.