My hat goes off to those guys. Anyone that can design a vehicle (Cherokee in this case) whose body can last for YEARS, while made out of metal just slightly thicker than your average two-ply bath tissue has GOT to be a genius.
I've spent the last couple months (off and on) replacing the entire bottom of a 94 Cherokee and have had fits trying to weld replacement sheet of some substance (16 gauge) to that tissue Chrysler called sheet metal. While the 16 turned out to be something of overkill, it should last quite a while. It probably would have been easier to weld 20 gauge to whatever the stock material is, but at least the floor has got some substance to it now, especially since I had no convenient way to add any stiffening bends to it.
I know one thing, the future includes a plasma cutter. Cutting all that sheet with a 4 1/2" grinder and cut-off wheels blew great big goats I'll tell you.