I changed out my fuel filter 4 months ago just after I got my truck but its situated well back and under the windsheild on a Hummer so I never got a good peek down inside. I started my FTB mod today so pulled the whole FFM out. When I took the top off and pulled the filter I nearly dropped the housing while laughing. Crumpled down and packed in the recess of the base under the filter is a complete shop rag. I think. It has the feel of the waxed paper new parts come wrapped in but could be a blue disposable shop towel thats been well treated with diesel for what Im guessing is over 10 years.