One problem related to rear axle spindle has been reported for the 1999 Hyundai Sonata. The most recently reported issues are listed below.
Just everyday driving to and from work, the usual speed bumps ( taken at normal speeds for said speed bumps) the steering pulls to the right, significantly, and the front right tire is at an angle instead of perpendicular to the road. The k-frame has rotted out and caused the front left spindle to bend, making the vehicle undrivable.