OK, we fell for it too. Our salesman said no cabin air filter in 2007 Edges. The book said change it if equipped; well, not equipped, so nothing to do. But it is now 2011 and the A/C performance has gotten really bad. Thought it might need a recharge of refrigerant, but no, the air output temp was 46F. Checked this forum and went looking for the cabin air filter. Didn't find a filter but, wonder of wonders, I did find something flat. Took it out and cleaned it up and guess what I saw --- a screen inside all of the debris. Put the screen back in and now the A/C works good as new. I wonder why we had to find out the hard way?
Well, never mind, it's working good now.
This is the third time this forum has saved me Lotsa$$$. Thank you FordEdgeForum.