In a letter dated August 9, 2013, Hyundai-Kia America Technical Center, Inc. (Hyundai) notified NHTSA that Hyundaiis conducting a safety recall (13V-354) involving approximately 239,000 vehicles involving model year (MY) 2006 through 2010 Hyundai Sonata vehicles (approximately 215,000)produced beginning on March 1, 2005 through January 21, 2010 and model year (MY) 2006 through 2011 Hyundai Azera vehicles (approximately 24,000) produced beginning on September 27, 2005 through November 22, 2010 that are registered in and operated or originally sold in the following 20 salt belt states and the District of Columbia: Connecticut, Delaware, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia, and Wisconsin.Hyundai will also inform dealers to inspect/repair vehicles that were previously registered in salt belt states but are currently registered elsewhere. Hyundai is conducting the recall to remedy a defect involving internal corrosion of the rear sub frame that may lead to separation of the rear upper/lower control arm(s) at their respective mounting points and/or separation of the axle from the transaxle where they meet.This could result in a loss of vehicle control and/or vehicle disablement which may increase the risk of a vehicle crash.In response to NHTSA?s Information Request (IR) letter, Hyundai stated the Azera vehicles utilizes the identical cross member and upper/lower rear control arm components as the subject (Sonata) vehicles.In analysis of both Vehicle Owner Questionnaire (VOQ) data submitted to the Office of Defects Investigation (ODI) and consumer complaint data submitted to Hyundai, ODI identified 19 non-duplicative reports alleging excessive corrosion of the rear sub frame. All of the complaint vehicles were either originally sold or registered at the time of the incident in one of the salt belt states.Of these 19 reports, 9 alleged either a suspension component separation or a fracture of the vehicle's rear cross member assembly.Similarly, ODI identified 8 warranty claims of rear sub frame replacement in data submitted by Hyundai due to excessive corrosion, all of which involved vehicles originally sold or operated in a salt belt state. Based on Hyundai's decision to conduct a safety recall, (13V-354) this investigation is closed.The VOQs cited above can be viewed at www-odi.nhtsa.dot.gov/owners/SearchNHTSAID under the following identification numbers: 10535115, 10534110, 10525976, 10524726, 10521520, 10508368, 10505463, 10490073, 10486752, 10486435, 1048354, 10473922, and 10437887.