In December, our itinerary is Regensburg (2 nights), Garmish (2), Lindau (1), Konstanz (2), Basel (2), Strausbourg (3), Nuremburg (2). We have a car rented at a good rate between Regensburg to Nuremburg. Questions I have are: 1)Some routes between Garmish & Lindau could go into Austria. Do I need a vignette on secondary roads only? 2)Konstanz to Basel - Preference for drive on Switzerland side or German side visiting interesting towns? I know I'd need a vignette if going Switzerland side, but if we did German side, do I need it just driving into Basel? I don't really want the car in Basel but want the car from Basel to Strausbourg for next couple days visiting variety of towns on wine route. I couldn't figure out way of dropping car before Basel and then picking up/dropping off in Nuremburg without hefty drop off charges.
The vignettes are for driving on the autobahns, not secondary roads. However, be warned the in the alps some of the autobahns are only two lane roads and don't fit the usual image of an autobahn so be very careful about the highway numbers if you go without one. Get the vignettes at the border or before you cross. Also remember that in Austria you will need and IDP. If something goes amiss and you don't have one life gets very expensive with an unlimited downside if you have an accident.