OK, here is what I think I know. The Jetta has electric/electronic steering. It is very responsive and accurate. So, VW designed an electronic system to compensate for crosswinds, road crown and the like. It seemed like a good idea, to reduce driver load such as constantly holding a slight pressure on the steering wheel.
Too bad it is so sensitive. It will over compensate for the road crown or wind (such as passing a truck). My car was unsafe. I am a trained, experienced race car driver and it took all my concentration to drive my car straight.
So, with the advice from this forum, I found a guy with the Vag-Com hookup cable and laptop. He adjusted my steering setting from an initial "3" to a "1".
Anyway, after driving many Jetta, I have discovered that no 2 have the same sensitivity. Some cars wander and some are rock solid.
Really does not matter much as it is easy to adjust the problem away.
Some here will say that you are adjusting the steering effort. But that is not true. You are adjusting the steering compensation setting. If you set it to "0", the car will not be any stiffer steering, it just won't have any electronic compensation for crosswinds and the like.
Whatever your initial setting is, try 2 numbers lower. A change of only 1 is difficult to impossible to discern.
Chris