Well, after reviewing our trip itinerary, we've canceled the rental car and are taking the train from Berlin to Rothenburg ob der Tauber and on to Koblenz two days later. I see a Spar-Preiss fare of 209euros (for the 5 of us) to Ansbach and then I think we can hop on a train to Rothenburg. It's on a Saturday but the Schones-Wochenende route takes 9 hours, and this is quite a bit shorter. Do these fares go up? Should we buy them now?
Also does anyone know which train station in Koblenz is closest to the SIXT car rental location on Friedrich-Mohr Strasse? Thanks for your help.