I'm looking for the return air intake. I need to spray some Wurth A/C & Heating System Treatment into it. Does anybody know where it is on the Z? On the directions it states to look under the passanger side, but I cannot seem to find anything under that looks like a vent. The only thing I see are the vents where the air comes out from when you set it to come out from the bottom.

Did not know if this was the right section.