I had some bad rust on my XJ's floor, ie BIG holes. I wire brushed all of the rust off, patched in new flooring where needed, treated it with POR15(both sides) and then used some roll on box liner from CT(Hippo Liner). Worked awesome! WAs very impressed with both the POR15 and the Hippo Liner. Very easy to use, in fact my wife applied most of the Hippo Liner.