I recently purchased a 2010 Navigator. Decided to size down a little from my 07 Expedition EL. Its amazing how much more refined the Navigator feels from the Expedition. I honestly assumed that they were 'identical' except for grill and seats. Had a question about the air box in these things. I am guessing that they are the same with the 2010 Expedition. In the future, I wouldn't mind trying something different for the air tube, filter, box. I see the washer tank is attached. Never would have thought this to be the case. Has anyone ever modified this?