I also have the driver's seat SQUEEK in my 2003 4.6L with sport seats (black with silver alcantera).

I have a service appointment for next week (to take care of a whole slew of issues!) and the seat squeek is on my list. I find it absolutely unacceptable for the seat to be squeeking each time I get in/out or take a corner or just shift my weight. Very annoying!