I have noticed my navigation system gets lost despite the fact that I have a brand new CD in there etc. In the information page of the info system I notice that the lat/long information is wrong and that the direction is wrong i.e. it reports car heading south when it is actually heading west. However, I notice this mistake is consistent i.e it will report going north when I am actually going etc and so on.
On some occasions it does find itself and then onward works well for some days till it is cloudy or I am in the city with tall buildings around.
My hypothesis is that the navigation antenna unit or connections to it has gone bad. A trip to the dealer revealed that everything needs to be replaces at 3K+ and to make obscene amounts of money on me.
Any suggestion will help me diagnose and fix it. & no I don't have a VAGCOM yet .