In a letter dated April 14, 2009, Hyundai-Kia America technical center, Inc (Hyundai) notified NHTSA that hyundaiis conducting a safety recall of model year (MY) 1999 through 2004 Hyundai Sonata vehicles manufactured prior to November 20, 2003 that are registered and operated in the following 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 is recalling the vehicles to remedy a condition where internal corrosion of the front subframe may lead to separation of the lower control arm at the forward mounting point and/or separation of the axle from the transaxle.this could result in a loss of vehicle control and/or vehicle disablement. The subframes will be inspected in the recalled vehicles using a procedure developed by Hyundai to measure metal thickness.parts with perforations from corrosion or with metal below the specified thickness will be replaced with redesigned subframes.if the minimum metal thickness is met, drainage holes and rust proofing material will be added to the existing subframe. ODI's analysis of complaint data revealed that 98% of the consumer complaints were from vehicles either originally sold or operated in saltbelt states. Similarly 99.7% of the warranty claims were from vehicles originally sold or operated in saltbelt states.ODI identified 105 reports of lower control arm detachment and/or axle separation from the transaxle through analysis of warranty and complaint information and consumer interviews.one hundred three (103) of the 105 incidents involved vehicles in states covered by the recall.in addition to the subject vehicles, Hyundai also noted in the April 14, 2009 letter that MY 2001 through 2004 XG300 and XG350 were also being recalled as they were manufactured with subframes similar in design the subject vehicles.based on Hyundai's decision to conduct a safety recall this engineering analysis is closed.