Saw my Expy at the shop...Left fender was removed (along with front bumper, grill, etc.) I noticed corrosion and rust had already started where fender attaches to inner body support panel(on the outside of the inner panel). It's just down beneath where the hood hinge is. Ford installed some type of tape (I guess for dissimmilar metals?). I showed the shop manager who was surprised to see it. The other side had not been removed yet. He said it's where the water drains from the vent assembly hood area. If I get a chance I'll take photos for posting. Might be of interest especially to northern or wet climate owners.

99 Expy EB

 

Another thought:
My 2000 Expy rusted in the roof channels near the windshield. Apparently, water collects at the front of these channels due to the stance of the vehicle. My vehicle was covered by warranty but I fear it may happen again in the future.