The air conditioning filter may clog after long use. The filter may need to be cleaned or replaced if the air flow of the air conditioner and heater experience extreme reductions in operating efficiency, or if the windows begin to fog up easily.

To maintain the air conditioning efficiency, inspect, clean and replace the air conditioning filter according to the maintenance schedule. In dusty areas or areas with heavy traffic flow, such as inner city or desert areas, more frequent cleaning or early replacement may be required.

1. Open the glove box and slide off the damper
2. Push in each side of the glove box to disconnect the claws
3. Remove filter cover
4. Pull the filter out of the filter outlet. If it's dirty, it should be cleaned or replaced.

Cleaning method:
If the filter is dirty, clean by blowing compressed air through the filter from the downward side. (Do not clean with water!)
Hold the air gun 5cm (2in) from the filter and blow for approximately 2 minutes at 500 kPa (5.0kgf/cm² or bar, 72 psi).
If it is not available, have the filter cleaned by your Scion dealer.

Replacement method:
When inserting the filter in the filter outlet, keep the arrow up mark pointing up.

*please see your owners manual for illustrations

right out of the owners manual... but you know as well as I do that many people don't read that

at least the gen 2's came with the cabin air filter installed.

I ordered my Gen 1 from the dealer before I read the posts on how-to cut up the HD ones

when you say 'If the filter is dirty, clean by blowing compressed air through the filter from the downward side' does that mean to turn the filter over and blow through the bottom of the filter?

just wanted to be sure...