Federal safety regulators have expanded an investigation into rust in wheel wells on Ford and Mercury minivans that can become unsafe.
The National Highway Traffic Safety Administration says on its website that the rear wheel wells can rust so thoroughly on Ford Freestar and Mercury Monterey minivans that owners can't latch the third-row seat properly.
Investigators began looking into 2004 model year vans in December. Now they're studying data from the 2005 through 2007 model years because the seat designs are like the 2004 vans. The probe covers more than 82,000 minivans in states where salt is used to clear snow.
The problem hasn't caused any crashes or injuries. The safety agency has upgraded its probe to an engineering analysis. The vans have not been recalled.