Two problems related to power train driveline have been reported for the 1999 Hyundai Sonata. The most recently reported issues are listed below.
Vehicle had developed a front end alignment problem, and I scheduled an alignment. The morning before the scheduled alignment, I was pulling out of my driveway to go to work when the right inner cv joint disintegrated. Investigation revealed severe subframe corrosion resulting in the control arm mount separating from the subframe, causing the cv joint to fail and the vehicle to become inoperable. Nhtsa and Hyundai issued a recall in 2009, campaign id number: 09v124000. However, the state I reside in (nebraska) is not listed as a "salt belt" state and is not covered by the recall. Nebraska does indeed use salt on the roads, and the description of the fault and potential results matches exactly with the rust and corrosion on my vehicle's subframe and the results. I believe it likely that there are other motorists in the state of nebraska who are driving these vehicles with this hidden and potentially very dangerous fault. The Hyundai dealer has been unable to help me so far with a fault resolution per the recall.
Hyundai Sonata GLS engine cradle rust one side. Tire dealer found and declared car unsafe to drive. 1999 v6 89500 miles - never wrecked or off road - driver side looks clean passenger side has a large hole in it. 861968 Hyundai complaint #861968.