Munich car rental south city?

Where are you coming from and how are you getting from this location to Munich?

To head south / west, renting a car at the main station (Hbf) isn't too bad. You have to drive about 1 mile in a straight line on the street north of the station, then you hit the inner ring-road with direct access to the A95 and A96 highways. Traffic flows very well outside of rush hour.
Otherwise, if Garmisch-Partenkirchen is a destination for you, you have plenty of offices there.

Thank you very much for this info.

Try Sixt. They are my go to rental company in Germany. They have a location in Haidhausen close to the Motel One Ost that is convenient if you are driving S or SE towards Austria (plus no airport or Hauptbahnhof surcharge).

DJ

You might try “Landsberg am Lech”, “Starnberg” or if you plan to go there “Garmisch-Partenkirchen”.

But I would assume, that you will find the better deals by renting in Munich.
Near S-Bahn station “Laim” there are several rental car companies, from here it’s super easy to navigate. Just go south on “Fürstenrieder Strasse” and turn right on either the crossing with A96 going west or A95 going south.

To where are you trying to go?

Have you tried looking up train and bus transportation on the Bahn website? There just might be trains or buses to everywhere you want to go.

In over 160 days of traveling in Germany, I've never needed a car.

I agree that a car isn't a necessity, but my DH has other ideas! So I am indulging him, but want to stay out of cities and high-traffic areas.
We are headed to Chiemsee and the Berchtesgaden areas, coming from MUC airport.

we are headed south/south west.

Excuse me, but Chiemsee and Berchtesgadem are mostly east of Munich. And both are readily accessible by rail. I've been to both, Berchtesgaden four times. Again, never needed a car.

Chiemsee and Berchtesgaden are southeast of Munich.

Pick up the car at the Munich airport where you will find the best car selection.. Also, you won't have any problem with getting transport to an "off site" car rental location where they may claim "Ich nicht sprechen English". Be sure to inspect the car for prior damage and have the car rental company document any prior damage on the car rental papers. Follow this same inspection/documentation procedure when you return the car.

Some folks pick a spot close to the airport to spend the first day overcoming jet lag. Your decision..

Pick up a good map of Bavaria (Southern Germany) so you can get to your destinations without getting lost. You can use the autobahns to get from the Flughafen (AKA airport)) onto A8 toward Salzburg without entering the local Munich traffic.. Study the map as there are several chances to make a mistake and get on A8 and wind up in traffic on the north side of Munich. Take A92 from the airport toward Munich then A99 East to A8 in the direction Salzburg . I usually use Google maps and take hard copies ..

Have a great trip!!!

I recommend to spend a night in Erding or directly at the airport before you picking up your car. The next day I would not use the Autobahn but the Bundesstraße (easy to drive as well) which brings you not only to Chiemsee but as well to Wasserburg am Inn (50 minutes ride from Erding to Wasserburg).

Wasserburg is a loverly little town and always worth visiting it: https://www.wasserburg.de/en/sightseeing/impressions

Thank you everyone for the suggestions ( and correcting my direction of travel--plans have changed re: our itinerary several times, so direction of travel has become flexible). We appreciate the input and the good ideas.

I always use Sixt for car rentals in Germany. If you are going to leave the country (cross the boarder into Austria) make sure you tell them so you have the correct documentation. If you can't drive stick you may have trouble finding a car. Pick up at the airport (as previously mentioned.) Traffic in most major cities is not like in the USA. Be very aware of what the signs mean and pay attention; they can and will ticket you by camera (and those are everywhere).

Thank you for all the great thoughts and ideas--we do appreciate them!

One more thing;

While cars will have navigation it is very important to know where you're going and how to spell it. For example; there are two cities, Regensburg and Regensberg, and they are 100km apart. Another example: there are (at least) three cities named Rothenberg, only one of which (Rothenberg od Tauber) is the common tourist destination.