Car vs. public transportation and itinerary help

"We are flying from Dublin to Munich."

It's a curious thing that you've already chosen to fly into Munich specifically. Your "sister" lives far from Munich and you don't mention any new things that might have drawn you back there. From Ireland you might be able to fly into Basel, Strasbourg, Stuttgart, or Karlsruhe/Baden-Baden, see some new things in that area, AND be closer to your sister.

But assuming that what is done is done, I'll ask what your sister's parameters are for meeting up with you. Will you accomplish this in Freiburg? Is she able to meet you half-way, or travel to Munich to meet you there? Would she be driving, or using the train?

If she can get to Lindau, that might be an interesting option. During your stay in Munich, the four of you could ride a direct train to this attractive town and back to Munich the same day. It's situated on an island in Lake Constance (Bodensee) near Austria and Switzerland. It's not a short trip - about 2.4 hours each way. But it would be an easy and inexpensive journey. Sample schedule...

Lv Munich 9:54, ar Lindau 12:16

(5.5 hours for lunch, visiting, sightseeing)

Lv Lindau 17:46, ar Munich 20:05

Ticket: Bavaria Ticket, a day pass priced at €54/4 persons. Buy at a ticket machine in Munich.

Lindau: https://www.nuernbergluftbild.de/images/T02140363a.jpg

Hi Russ, thanks for your reply. I had mentioned that Dachau is a must, so that was the intention behind flying to Munich, but I guess we wouldn't have to fly there directly. If we didn't do that, she is willing to travel to meet up with me. I'm not sure what transportation she would use, I think train. I will look into Lindau, thank you!

The Dachau must-visit could be accomplished in 2.5 hours each way from Stuttgart by train, which is much closer to Freiburg (2 hours or less) than Munich; Stuttgart splits the difference. It would also offer nearby options such as Tübingen, Esslingen, the Black Forest, Strasbourg, and Neckar River destinations such as Heidelberg, Ludwigsburg, Bad Wimpfen, Guttenberg Castle, and Besigheim.

But maybe all that is for your next trip... From MUC airport: Dachau is just as close as Munich (40-45 minutes) and its attractive old town zone has several hotel options. You could probably get there, drop your bags, have lunch, and proceed to the camp on your first day if you wish. The bus ride from town to the KZ camp takes just 7 minutes.

After that, well, Bavaria is your oyster. You asked for "some new things." You went to Rothenburg before, but missed out on the rest of Franconia (an impressive subregion of Bavaria known for its breweries, wineries, cuisine, and culture and situated to the north of Munich.) Below are some of my favorite places. All are accessible by train, and with 4 traveling together, the Bayern (Bavaria) Ticket day pass mentioned previously is a thrifty way for the 4 of you to get to some of these places. You can research most of them online. I will toss in a few links for the lesser-known destinations.

Nuremberg (Nürnberg) - it is a rail hub and an excellent base town for visiting most other Franconian destinations
Weissenburg (Weißenburg) - see photos
Eichstätt
Pappenheim (not on map, near Weißenburg) - see photos
Bamberg
Coburg
Bayreuth
Würzburg
Bad Windsheim
Iphofen (small like Rothenburg, not on map, near Würzburg; see photos.)

Does it have to be Ireland first, Germany in the middle and then London? Ireland-London-Germany makes a bit more sense from a geographical point of view.

When you say Germany, do you mean Germany or do you mean Bavaria? Most of the places you mention are in Bavaria, with a few in other states and a few in Austria. But there is a lot to see in the other 15 states as well. And is Dachau a must, or is a former concentration camp a must? Dachau was unfortunately not the only one. But a few days in Freiburg is not a bad idea, it's a lovely town.

Germany has a great public transportation network, so use trains.

We stayed at the Hotel Burgmeier in Dachau and were pleased with it. It is less than 5 minutes walk from a S bahn station on level ground. The bus to Dachau was about another 5 minute walk away and very easy to access. This hotel is family run and they take pride in what they do. The prices are reasonable and the rooms modern and clean.

Germany has terrific public transport. If you will be taking regional trains, buses, trams and the "D" ticket is still in effect, you save an incredible amount of money using it.

@Russ, this is helpful insight, thank you!

@Badger Yeah, we're flying into Dublin and then out of London to go back to PHL. It could be anywhere, but I was leaning towards Bavaria as I enjoyed what I got to explore there before. I didn't see that there were any other concentration camps that could be visited in Bavaria.

@Carol Thank you for the hotel and travel tip

What does the OTHER COUPLE want to see/do ??

Well out of your way, but I am 20k from Flossenbürg concentration camp. (Bavaria). There were work camps around Bayreuth too. Maybe Nürnberg as Russ suggested? The Oberpfälzer Wald is really nice, and you won't find many tourists here. On the border with Czechia. This would be a car trip. From where I'm at you can drive to Prag in a little under three hours (E50 toll road).
https://www.gedenkstaette-flossenbuerg.de/de/

Ideas of where to meet my foreign exchange student? We will be leaving
Germany to then fly to London.

With all this being said, rent a car for the 4 people or take other
form of transportation?

If your exchange sister is going to travel part of the way to meet you, then I agree with Stuttgart as the meeting point. I was there in October and throughly enjoyed the city. Munich to Stuttgart by train is my recommendation. Note: Stuttgart HBF is undergoing a massive construction project. Long walk from platforms to the station entrance.

If you go to Freiburg to meet her, then a car from Munich is your best bet. You will also get to visit the small towns and back roads of a part of Germany that I have not yet gotten to and that most Americans never see.

Meeting your exchange student sister why not do it in Freiburg and see the sourounding area?
Nice city with lots to see and do.

On the way from Munich see places like
1)Oberammergau(little detour) Neuschwanstein Füssen

2)Lake Constance with Meersburg and Mainau Island and Konstanz
3)drive through Black Forest to Freiburg
4)Back to Munich via Lindau

Stay in places 1 to 4 in one of the towns bold for 1 or 2 nights each
Driving around 150km each day

@Stephen the other couple (my mother and father in law) asked me to present options after my research. They weren't sure what they wanted to do.

Thank you all for your input. After looking at many options, I presented a few of them to my in-laws. They are interested in Munich, Dachau, and Lake Constance. We are interested in a city/small town mix including a little history, light hiking or biking, and yummy food/wine.

Below is what we are considering.

Day 1: Dublin to Munich
Day 2: Munich with visit to NS-Dokumentationszentrum Museum and Dachau
Day 3: Munich to Fuessen (biking, tree top walkway, Neuschwanstein)
Day 4: Fuessen to Lake Constance (Stay in Lindau, Meersburg, Konstanz, Mainau?)- could maybe visit Tübingen or another small town from here or Lichtenstein Castle?
Day 5: Lake Constance
Day 6: Lake Constance to Munich or Stuttgart (depending on flights)
Day 7: Munich/Stuttgart to England

What do you love to do in the Lake Constance/Bodensee region?

Would you try to take the train from Munich to Fuessen and Fuessen to Lake Constance? Would we need to rent a car for day trips from the Bodensee (for example, if we went to Lichtenstein Castle) or are there trains?

Thank you for all of your help!

Sorry you cant stay overnight on Mainau Island unless you know Graf Lennart Bernadotte in person.;o))
The island is private property as far as I know Gardens are open to the Public

https://www.mainau.de/en/home

So better stay in Konstanz Meersburg or Lindau
.
I would choose a rental car for travelling to those places. Less time of travel and you can stop on the way where you want to.

My option for a overnight stay on Lake Constance would be Meersburg nice little town opposite to Konstanz and the Mainau Island
You can go to Konstanz and Mainau Island by Ferry from Meersburg (as well car Ferry as Person)

Meersburg
https://www.meersburg.de/en/Tourism?showHomeAlternatively=1

Konstanz
https://www.constance-lake-constance.com/

Coming from Füssen you first reach Lindau its historic center is a on a peninsula in the lake Worth a visit.
You can go there straight from Füssen or from Meersburg if youll stay there (ca 1hr drive)

Lindau
https://www.lindau.de/en/

You can check these links which give good info about the Tourism in those places
Cant say much about accomodation cause we stayed in Holiday Appartments on the lake and they dont do short stays sorry

Finally a link to the Bodenseeschifffahrt (Boats and Ferries on Lake Constance)
https://www.bsb.de/en

I would stay in Meersburg. Nearby is the Pfahlbauten Lake Dweller open air museum and the Birnau baroque church, both worth visiting.

If you fly out of Stuttgart then You could visit Schloss Lichtenstein and Tuebingen on the way there.

@uwe04 hahaha thank you!!

@stephen thank you for your help as well