Frankfurt to Baden Baden and heading south

There are several rental car locations in Loerrach, Germany. Europe Car is about 1/4 from Loerrach-Schwarzwaldstrasse station, Sixt is even closer, Hertz is close to Loerrach-Brombech/Hauingen station. These all have trains every half hour to Basel SBB station where you can catch a train to Interlaken.

Thanks Sam
That sounds easy. I rent from Hertz here in the States so maybe I'll just go with them.

One more question about car rental: we arrive at Frankfurt airport and will stay in the city. Do you recommend that we get a car at the airport or can we pick up a rental in the city, perhaps at our hotel?
Carol

Before choosing a rental company - and maybe before deciding you need a car at all - it would be wise to read about the experiences of previous car rental clients. You'll find many such threads at Tripadvisor like this one on Hertz:

Rental car scam by Hertz

Also FYI, the Black Forest is criss-crossed by rail lines, and when you stay in any of 140 participating villages (like Badenweiler) you receive a "KONUS" guest card and can use the extensive Black Forest railway system for free (buses too if needed) to go wherever you like (including Basel.)

KONUS card information

"I'm just not sure that Badenweiler is the right place to stay. I kind of want to stay deeper in the Black Forest."

You'll find some very attractive places closer to the geographic center of the Black Forest region. Suggest you consider the following charming towns:

Schltach and Wolfach
Haslach

Any of these towns would allow for easy outings to the old walled town of Gengenbach and the delightful Vogtsbauernhof open-air museum.

Hi Russ
I was kind of considering whether we should take a train to Baden Baden. If we did that, we could actually leave from the airport (as I understand it, haven't been there) and get to our destination the first day.

My husband and I both enjoy driving so I was thinking the train might be a hassle. But I noticed that while we are in Baden Baden we won't need a car except for trips to the countryside.

Is there a place I could go to see all the rail lines? I will google the KONUS pass and see what I find at their website. Thank you for taking the time to help me out!
Carol

www.bahn.com is the go-to website for German trains.

You can indeed catch a train from FRA to Baden-Baden.

Carol: "Is there a place I could go to see all the rail lines?"

This schematic shows the major lines that criss-cross the Black Forest. Most of them can be traveled using the Konus card (but Stuttgart and Strasbourg are not included.) #4 is the scenic Black Forest Railway:
BF railway lines

This is a smaller section of the BF core area is geographically more correct and shows the scenic BF Railway in red and a few other lines too:
BF Core area

This map shows not just the BF area but the entire state of Baden-Württemberg:
B-W rail line map

Rick's Germany book also shows rail lines on the map on p.272 in the Black Forest chapter. You'll see there that rail can take you a lot of places, although he's designed his scenic driving suggestions to detour away from the rail lines.