Help with base locations for a 3 week self drive itinerary!

What does "Southern Rhineland" mean to you?

Have you looked at Pfalz? What do you think of Deidesheim?

You say you are reading all the tourist books but your list looks very Rick Steves. Have you looked at others too?

Yes, I'm reading Lonely Planet and Rough Guide, as well as researching other people's itineraries - I'm not locked in to any particular itinerary. When I travel I like to have base locations and then really plan out from the base.

Yes, I'd like to stay in the Pfalz area -I just need to determine where. I'll look at Diedesheim to see if that might be a good fit.

Thank you for your suggestions.

"Prefer smaller towns to larger cities."

Heidelberg, Munich and Freiburg do not qualify as small towns. I suggestion looking at other options.

Near Heidelberg: Bad Wimpfen

Black Forest: Freiburg's not really in it anyway. This is a large area with many good options. You likely won't see it all. Consider Calw, Schiltach, Gengenbach, Gutach Schwarzwaldbahn, Löffingen.

Bavaria: Simply huge and overwhelming. You need at least a northern base as well as a southern base. Stay in Füssen or Rothenburg only if you require proximity to throngs of international tourists. There are many other excellent options.

"Rough Guide" will serve you well in planning the trip. That's the one I consult exclusively for trip planning, be it in Germany or other countries in Europe.

If you decide that area, I would suggest seeing Rastatt also.

Well I've stayed in Baden-Baden and Heidelburg and can't really comment on the smaller towns over that way. But for Bavaria i'll recommend Bad Windsheim, Ansbach, Nordlingen, Ettal, Garmisch, or Bad Tolz. Augsburg, Nuremburg, or Ingolstadt if you want a bigger place. Frankly for Munich I'd stay in the city, but in Schwabing (southwest) or North in the University district. I'd never stay in Fussen, and if you have to stay in Rothenburg odT you can find a cheap gasthaus south and east of the city walls.

If you have 3 weeks in September why do you not plan to visit also other German regions? The northern part or Berlin around this time of year are really beautiful.

A second for Bad Wimpfen. Hilly, cobblestone, ancient, medieval, beautiful, quirky, scenic and quiet.

And a very modern very cool fabulous hotel just across the road from the Altstadt that I am happy to recommend - the Neues Tor. https://www.neuestor.de/de/ A little more expensive (but people who know me know I am cheap) but worth it.