One bit of advice...dont go poking around the semas too much..youll find what your looking for if you do. That is, the idiotic engineers or maybe the ben counters who decided where to put seam sealer, on the inside seams, not the ouside. As a result moisture gets in between the seams and just sits there. The moisture does not make its way into the Jeep due to the sealer, but when it finally does its because your sheetmetal has completely rotted away.
Had those idiots put seam sealer on the outside seams, like you find in a Mercedes, then our Jeeps would last a whole lot longer without serious repairs.
Ive messed around with many XJs and have found the above to be true in every case.
My 92 which looked extremely clean when I pulled the rug to install the roll cage...after a little poking around at what appeared to be pristine floors, it was quickly revealed that at nearly ever seam significant rust was to be found, except that the seam sealer was hiding the cancer. This was one of the reasons I was so delayed to getting my Jeep ready for Moab.
XJguy