I just lifted up the seats and carpets to my 745, and noticed a rust patch roughly 3x6 in an oval shape right around where the AC/Heater vents come out into the back seating area from under the front seat. I noticed that this was an inside-outside rusting effort that apparently started from underneath some sort of liner that is glued to the floor pan. This is a good sized rust patch (yet isolated), and right now all I'm doing is knocking it out and have begun to take the drill with various sanding bits to the rust to clean things up. I want to get this thing closed up fairly quickly, so what's the best method? Fiberglass is sloppy, welding is expensive, etc. I'm cleaning it up so it doesn't spread, and I kind of want to slow the rust down as much as I can. I'm looking for a fix that'll last a few years before needing to be fixed again. Something to tide me over. Any suggestions? Polyurethane? Somethin else?