VOLUNTARY SERVICE CAMPAIGN - APPLICATION OF ADDITIONAL ANTI-CORROSION MATERIAL (SC264): This bulletin has been revised to include additional information. New/revised sections of this bulletin are indicated by a black bar in the margin area. This bulletin provides information to apply additional anti-corrosion material to the underbody components on certain 2012-2017MY Rio (UB) and 2017-2018MY Forte (YD/YDm) vehicles produced within the date ranges shown below and originally sold or currently registered in one of the 28 states where heavy amounts of road salt are used. The 28 states where heavy amounts of road salt are used are: AK, CT, DC, DE, IA, IL, IN, KS, KY, MA, MD, ME, MI, MN, MO, ND, NE, NH, NJ, NY, OH, PA, RI, SD, UT, VT, WI and WV. Corrosion can occur due to a combination of environmental conditions and lack of proper underbody maintenance, especially on vehicles in states where heavy amounts of road salt are used if the materials used for ice/snow removal are not regularly flushed from the underbody of the vehicle.