One problem related to speed control linkage has been reported for the 1998 Audi A6. The most recently reported issues are listed below.
The throttle sticks in cold weather causig the Audi A6 wehicle to accelerate on its own without pressing the gas. This has happenned to me several times this winter and last winter. I reported this last year with no satisfaction. It is a dangerous situation and Audi should be held accountable. I have contacted them several times, but they continue to ignore the problem. I know of at least twenty other vehicles of this make with the same problem.