[:@]What is that anoying little rattle that you can just make out when it's quiet on the left side of the drivers seat down by the floor. I hear it in my 99 power stroke, my work truck "00" gas, my friends 05, and another friends 05. We think we are nuts!!!

 

Your statement, We think we are nuts!!!"you got it.

Remove the inside door panel and tighten the nuts for the door latch. It used to drive me crazy, until I checked the door latch. The nuts were all loose.