The National Highway Traffic Safety Administration is looking at about 100,000 Ford and Mercury minivans that were not included in a recall for rust issues. In March, Ford recalled almost 230,000 Ford Freestar and Mercury Monterey minivans to fix a rust problem that can cause the third row seats to loosen. The vans range from 2004 to 2007 models and were registered in 20 cold-weather states, where they are easily susceptible to rusting.