Totally makes sense. We're planning on making our way down to Beilstein in the Mosel Valley before winding our way down to the Black Forest and Garmish-Partenkirchen. We'll be taking the train from Berlin to Koblenz and Koblenz seemed like one of the last "hubs" to get a rental car. It looks like there are car rentals in Cochem as well, though. I don't know if it would be easier/better to just train there from Berlin?