Well it looks like the only factory that did the sealant is Lago Alberto in Mexico. Saltillo in Mexico and St. Louis in USA did not do the sealant? Still wonder why? My truck was built in the Lago Alberto plant and the quality is first class (of course the build quality of my 2000 that was built in St. Louis was also first class just no sealant). Of the three assembly plants Lago was shut down after the last of the 2002's were built. I think Lago was the oldest DC plant in Mexico, maybe since they were not as automated they did the sealant???