Then I thought: "How about that truck box-liner stuff?" It could be sprayed at least 1/4" thick, and is designed for heavy-scuffing outdoor surfaces. I'd spray everything that's usually carpeted, and then use removable plugs for all the drain holes (which were plugged on my car). I would have, in effect, a large plastic dish, 1-2" deep, for the floor. Much easier to drain and dry, presumably just as sound absorbent with removable mats, and decent-looking. After a decent metal preparation, it should seal and stick to the floor as well as any underlay I could put down.>
The only thing that I have to warn about in a coated floor is you won't believe how much dirt you track into a car without carpeting. I have another car that has no interior that I drive on the street, and take to = an occasional track event. It's floors are painted gloss black, and dirt see= ms to accumulate very quickly from the soles of my shoes. I began to realize=
that carpeting absorbs this dirt, and hides it deep in the pile. Admitted= ly this dirt has to be vacuumed out, but having a coated floor will only sho= w off this dirt, until it's cleaned up.
My $.02 worth.
Tom