I bought a 93 in 1999. The floor was so rotten that it had a hole in it behind the passenger's seat right above the muffler! I noticed it after I crossed a water hazard for the first time because about 3" of water came in! To let it out, we made a bigger hole through the floor with only a plastic window scraper! And it didn't even show in the dealership's pre-buy inspection I had them do!
So After that I had the entire floor cut out and replaced (There is no replacement floor since it is a unbody, i.e. the floor is welded to the frame rails.), zinc coated and painted. And about a month after that I got into an accident and wrecked it! The worst dammage was to my Ego and pride I think!
Then I bought a 96 in 2000. The floor was also starting to rust. So I removed the entire floor carpeting, sanded the floor, plugged the small pin holes and will paint it soon. I'm now drivin it without a carpet... Since the bottom layer is a thick wool layer for heat and sound barrier that also acts as a big sponge and rust accelerator. There is a plastic tarp right above that layer so the water can't get in our out. Then there is the actual carpet you put your feet on.
Without all the carpeting, the truck is a little louder and especially warmer. But I have now access to the floor's drain plugs and can see how healthy it is...
96 XJ Sport having the 6 cyl engine as the ONLY factory option
4" custom lift, 31" Yokohama Geolandar A/T + II, Quick disconnects, no rear sway bar