I have an 04 FX4 Reg cab w/manual slider which was sqeeking all the time. There was an earlier post that said to lube under the outside window seal, on the drivers side. I slipped a credit card under the seal and sprayed some WD-40 which stopped the noise for a while. It came back so I tried White Lightning grease and haven't heard it for 6 months now. I had to press the seal vigorusly in several areas to determine where it was sqeeking. Mine was on the top near the slider and at the extreme outside bottom. If you have a tonneu cover it's a real bear to get at the base. When it rained the noise always stopped since it was wet. Dealership said no TSB for manual slider when I brought it in......and yeah, it was raining so they never heard it. "Think McFly, think!"