My husband and I are driving/returning to Munich from Berlin on 10-5 through 10-9 and looking for the best area to stay we think in the Rhine valley. I am interested in light hiking, day river cruise, e biking, winery. We are not young chicks but can handle. We are doing historical Munich to Berlin and we love water, country and not a lot of stress. Thinking about Moselle but fearful of the 7+ hour drive from Berlin. Thinking about stopping at one of the car museums on the drive back to Munich. Any ideas to complete this round trip would be helpful
"...fearful of the 7+ hour drive from Berlin." Since you enjoy walking/hiking there is no need for a vehicle on the Rhine or Mosel Rivers in order to reach the towns and castles that most people wish to visit there. Let the train get you to the Rhine Mosel from Berlin....
I would take the direct 7:46 train to Cologne (4.5 stress-free hours) with arrival at 12:12. Store bags at the station and take a short break there. Maybe tour the Cologne Cathedral (next to the station) or just have lunch at/near the station.
Then I'd catch the direct train to Koblenz - takes about 1 hour. Koblenz is a rail hub for the Rhine/Mosel region. Spend your nights there, and it will be super-simple to visit the Rhine Gorge towns, the Mosel towns, or both. Focus on Koblenz > Bingen on the Rhine, Koblenz > Trier on the Mosel.
The Mosel Railway has multiple sightseeing options along both river banks. Stop in Moselkern for a gorgeous hike to Burg Eltz castle. Visit Cochem (cruise from there to Beilstein and back.) Visit Trier, Germany's oldest city.
https://www.mosel-inside.de/en/travel-guide/mosel-villages.html
The Rhine has two railways heading south from Koblenz, one on each riverbank.... this is considered Germany's most scenic train ride.
West bank: Visit Bacharach, walk the old town wall. Take a train to Bingen for a cruise to St Goar (Rheinfels Castle, hike up.) Stop in Boppard, enjoy the waterfront and the awesome chairlift ride there.
East bank: Take a 12-min. train ride from Koblenz to Braubach (handsome old-world town) and hike up to Marksburg Castle. Take a train all the way south to Rüdesheim (touristy but nice old-world town with a few amusements) to get a full view from the "other" riverbank.
Koblenz > Munich: I'd want the 8:48 direct train departure from Koblenz to Munich. 5.5 hrs, arrive 14:21.
"One of the car museums"... There's BMW in MUNICH. But if you mean MB, then you should route yourselves from Koblenz to STUTTGART Hbf station (the main station, lockers there for bag storage) and use the Neckarpark rail station to get to MB from Stuttgart's main station.
I agree that driving all the way across Germany is not the way to go. I would take the train to the Frankfurt airport and rent a car there, drive north along the Rhine and then west along the Mosel, staying in your preferred accommodation along the river somewhere. Return the car and take the train to Munich with a stop in Stuttgart as suggested in the previous post for a visit to the Mercedes Benz museum. Or do the Mosel without the car as also suggested above.
It's a 1.5 hour flight that costs around $125. That's how I travel between those cities. And you don't need to be to the airport more than 1 hour before the flight. I have done this twice this year.
Stay in Mainz for a night or two, visit the Rhine if the weather is clear; you have about a 40% chance of that, and then go down to Stuttgart on the train and do the Porsche museum. You could add the MBZ one if you overnight there.
Then take the fast train from Stuttgart to Munich. It's faster, and cheaper, than driviing.
"...light hiking, day river cruise, e biking, winery... we love water, country and not a lot of stress."
Mainz has wine but it's not a good place for the other stuff, and it's not a convenient base for the Mosel at all, a bit less inconvenient for the Rhine.
Koblenz: I suggested this town for the sake of convenient travel on both rivers. If Koblenz is too "big" for your needs, just stay in a village NEAR Koblenz. There are several good options. Boppard is a great base town just to the south on the west Rhine bank railway... with LOTS of rooms and dining options. Osterspai and Braubach are two very attractive smaller towns on the east bank railway. All three are short train rides from Koblenz and worked well for our stays in the area.
This video is mostly about Osterspai but shows of Boppard across the river and of the outdoor options nearby:
https://www.youtube.com/watch?v=V4E5FyzrK98
Winningen is another good small-wine-town option as a base town. It's on the Mosel, also just a few train minutes from Koblenz, on the railway to Mosekern, Cochem and Trier.