Two problems related to front suspension upper arm have been reported for the 1999 Audi A6. The most recently reported issues are listed below.
Suspension:front:control arm:upper arm is making noise when car is rolling. The dealer had to replace it since I heard on your web site that this could lead to the fall of front wheels. The car is less than five years and this should not happen.
Right front wheel assembly on right side of car separatedfrom car. The upper control arm broke causing the assembly to fall off the car.