One problem related to front suspension lower control arm has been reported for the 1999 Hyundai Sonata. The most recently reported issues are listed below.
Hi, I bought my 1999 Hyundai Sonata from a private person Nov. 2007. I was driving the car to the store when all of a sudden the right front wheel went back into the wheel well. I had it towed to a garage to lift it to see what happened. The engine cradle was so rotted that my half shaft pulled out and broke. The control arm completely rotted off the cradle. This is what I can plainly see as a safety hazard. I could have had a wreck had I been going any faster.