cabin air filter

Hi all: I'm sure everyone knows this, but here goes. I finally got around to installing a cabin filter. However there is no screw, under a plug, near the wiper blade. There is an indentation where it could go, but no plug or screw. You only have to unfasten the 3 clips, and gently wiggle the plastic cover on the passenger side, to get to the filter area. I must quit driving so much, my SVT turned 18,300 miles today. art in Ga.[wiggle]