E,
We probably need a definitive report on the issues with the US "factory" rack for the 80 series. (It was a port installed option.)
The report should include pictures and maybe a before and after. C-Dan has done the repair/repaint but most of us aren't going that route if we can avoid it.
The problem with the factory rack is that the 4 hard plastic feet that comprise the main mounting points, are not riding on a soft material like rubber or felt or some type of grommet. These 4 feet start cutting through the clear coat, cutting through the color coat, and on some trucks, have cut right down to the metal. When you get to bare metal something is going to rust.
Another problem is with the nutserts that are installed in the roof. These were installed by drilling holes into the roof. There holes were not properly protected with paint. Now they are starting to rust.
The final problem (I didn't check mine) being reported is with the long runners attached directly to the roof. It has been reported that these are also digging in through the paint at the tips on each end of the runner.
Everyone that has looked under these pads has found some degree of problem. Some in Rick's rust belt

have found pretty bad rusting. My truck has lived it's entire life here in Albuquerque with the occassional trip outside of the desert. We have no rain, no humidity, little snow, and no problem with salted roads. There was some light rusting at the nutserts. A couple of the pads had worn completely through the clear coat (note that mine's a late '97 !!).
Since I need a rack and haven't bought a proper expedition rack yet, I decided to do an interim fix. My pads are now riding on a softer plastic material that (hopefully) has stopped the damage from getting any worse. After I get the rack that I want the "factory" rack will be removed and repairs will be done similar to what C-Dan did on his.
-B-