As far as I'm told, you don't. 2006 Scion Xa's came with a tray where the filter would go, but there is no "Cabin Filter" for this vehicle. According to two of my Toyota/Scion dealers, though a filter might be made to fit, doing so would restrict the air flow because the vehicle air/venting system is designed to work without one. You can check with your Scion dealer, but this is what I was told when I was unable to find a cabin filter's at the parts stores and later, Scion parts itself.
There is no cabin air filter on the 2006 year model of the GMC Yukons and Denalis.
How to Replace a Cabin Air Filter on a 2006 GMC
The cabin filter is on the passenger side, near the middle of the dash.
4.2
The cabin air filter is located under the passenger side of the dash on a 2006 Grand Caravan. Slide the filter door to the side, and the filter will slide out for replacement.
GM decided to remove the cabin air filter option starting in all 2005 trucks. You do not have a cabin air filter in your '06 silverado.
I will post a link to a video I made on how to change the cabin filter on the 2003-up Accord. It is the same for your Element. Just watch the video.
2006 dodge carvian cabin filter location. Where is the filter located?
The 2006 Chevrolet Colorado does not have a cabin air filter.
2006 f150 xl cabin air filter location
How to change dashboard lights in primera 1999?
how do i install the cabin air filter in a 2006 honda odyssey