First time posting here - need advice plz

You do realize that you will pay a big international drop fee for the one way rental, and if it is a high end sports car from a specialized rental outfit, it will probably be extra big. The car will have to be transported back to Germany from Vienna and guess who pays for that.

Be sure to get an Austrian vignette for the car and have an IDP.

To add to Sam's post, it's a quick and generally inexpensive train ride from Munich
to either Innsbruck or Salzburg. If there is indeed a big dropoff charge for the car,
renting something in Austria, driving back into Germany for a bit, and dropping the
car off in Austria could yield a lot of savings. I think you might still have a dropoff
charge if you rent in Salzburg and drop in Vienna, for example, but nothing like a
cross-border charge.

AutoEurope and Europcar are two consolidators that might be worth a look.

Another option to avoid drop off fees is to take the train to Garmisch-Partenkirchen from Munich . Makes this your base for 2-3 nights. Rent a car locally to go to neuchswanstein, Zugspitze gondola. Return the car and take the train to Innsbruck. Rent there for the rest of your trip in Austria and avoid extra cross border costs.

Oktoberfest is fun but busy. Have a wonderful time.

Driving car in an around Munich is not fun. Munich is #1 traffic jam city of Germany; Autobahn ring A93 is #1 traffic jam Autobahn, also two other ones to / from Munich under the top 6.

If you want to drive a car in Germany ensure the validity of your driving license in Germany and possibly also the need for an IDP to have valid driving permission [not license only] in Germany.

Be aware that Autobahn is no race track and that German drivers are more educated for getting a driver's license and more used to fast speeds on Autobahn. I hope you know what it means to double speed for length of braking distance.

Cross-border rentals are nearly not possible with special cars. In Austria fast cars are meaningless anyway (speed limit).

Try German town Freilassing near Salzburg as drop-off at Sixt.

You can also try Hertz and Enterprise. Hertz has AMG available in Munich.

I wouldn't rent while staying in Munich, parking is stupid and it's easy to get around by public transport. That being said I have driven around Munich recently.

You might just want to consider taking the train to Innsbruck or Salzburg from Munich, picking up a car there, and then dropping it in Vienna at the end of your trip. You can do this and drive into, and around, Germany fairly easily.

If you're going to drive to Rothenburg, I suggest the route, Augsburg, Donauworth, Nordlingen, Dinklesbuhl, Rothenburg. It's not all Autobahn, but it's a good drive.

You're going to find a lot of the autobahn limited to 130kph, and a fair amount of roadwork also.

Thank you all for your responses and advice. After doing some considering this is what I’ve come up with for the trip. So far the only things I have locked in or the hotel in Munich from September 30 to October 5, and the Munich bike tour. I’m open to advice to change things. This is my second time in Germany and Austria I was there in 2019 but it’s my wife’s first time. we’re going to some new places I haven’t been but also a few places I’ve been before so my wife can enjoy it too, and most of them I don’t mind seeing again.

we land in Munich Germany September 30 in the afternoon and we leave Vienna Austria on Oktober 17 early morning going home to USA. That’s total 16 days, not counting the half day when we arrive.

September 30 - landing in munich at 1:30pm, by the time we get to hotel and check in will be 3:30 or later. Plan on walking around a bit, getting some food, and the rest of the day is open, might check out the festival in the evening. Negotiable and open to suggestions

Oktober 1 - plan on going to the festival in the daytime and will probably be there all day/night. Negotiable and open to suggestions  

oktober 2 - 11:30 am I booked a 4 hour group bike tour with English guide which will stop for lunch at a Biergarten, will be done by 3:30. The rest of the day is open we have no plans yet. Negotiable and open to suggestions

Oktober 3 - will probably go to the festival again this day and possibly stay all day but will see how we feel or if we want to do anything else. Negotiable and open to suggestions

Oktober 4 - we plan on picking up the rental car this day (BMW M440i) and driving to see some old towns outside of munich. One idea is to drive to Rothenberg and see the towns on the way, there are different routes which pass through different towns. Option A - Munich-Augsburg-Ulm-Rothenberg . Option B-Munich-Ingolstadt-Nuremberg-Rothenberg. I need to research those towns see which ones are more interesting (please suggest) and also which route has longer sections of no speed limit and less traffic. I’ve been to Germany in 2019 and driven an M car on the autobahn at high speeds responsibly, so I have experience and I plan on doing this safely and respectfully.

Oktober 5 & 6 - were checking out of our Munich hotel and heading south towards Garmisch, stopping at interesting places along the way. On the 5th we’ll start with Zugspitze in the morning, then head to Neuschwanstein until it gets dark, then back to town for dinner and sleep. On the 6th maybe we’ll go hiking in the gorge then to hang out at the lake Eibsee. Anything else you guys recommend in this area? The next day we’ll check out and head to Innsbruck

Oktober 7 & 8 - check out of our hotel in Garmisch and drive into Innsbruck Austria stopping at interesting places on the way.  Will be my first time in Innsbruck we plan on exploring the town, any recommendations in this town and surrounding areas? We will definitely do the alpine slide which is south of Innsbruck. We plan on staying 2 nights, probably not more so we have sufficient time in our next destinations

Oktober 9, 10 & 11 - check out of Innsbruck hotel and drive to Salzburg, stopping at interesting places along the way. We plan on staying not more than 2 or 3 nights so we have time in our next destinations. while staying in Salzburg we plan on going up to Kehlsteinhaus/eagles nest. I was going to spend a night in Berchtesgaden, but since it’s only 30 minutes from Salzburg and I plan on staying in Salzburg anyways, I might as well use Salzburg as a base and just drive to Berchtesgaden? I don’t like packing/upacking too many times it’s too much hassle so this will save me time. After Kehlsteinhaus I’d love to do more while in the Berchtesgaden area, open to suggestions. Maybe salt mines? Although later during this trip I plan on visiting Hallstatt / Salzkammergut so maybe I’ll see the mines there instead? I heard Konigsee is over rated but what do you think? Later in this trip I’m going to be in Salzkammergut Lake District near Bad Ischl which is surrounded by lakes, should I skip Konigsee? Anything else I should do before leaving Berchtesgaden?

Oktober 12, 13 & 14 - check out of Salzburg hotel and drive to Bad Ischl or any worthwhile town in the Lake District, plan on staying atleast 2 or 3 nights and enjoying the lakes and anything else there is to see/do. Please send any suggestions 

Oktober 15 & 16 - check out of Bad Ischl and start driving towards Vienna. I’ve spent a couple hours in Vienna on a layover before but all I did was eat some Schnitzel and walk around the city. This will be my chance to spend atleast one full day there, depending on how much time I spend in any towns on the way to Vienna from Bad Ischl. It’s a 3 hour drive but I figure it’ll take all day if I stop at a few places like gmunden/traunkirchen if they’re worth while. That’s if I don’t spend a night in those towns. Any places on this route  you guys can recommend? Considering the places I’ve been in the previous days, should I spend as much time as possible in Vienna? I feel like 1 or 2 days is enough for me in the big city, but if there isn’t much to see on the drive to Vienna, I might as well spend as much time in Vienna as possible. If I arrive in Vienna. On the night of the 15th and check into my hotel, that means I will have all of the 16th to enjoy the city before going home on the morning of the 17th. Maybe we could go to a classical concert or organ concert, always wanted to do that

thank you guys for taking the time to read my long text, looking forward to your responses, I really appreciate you all!

@KGC

thank you for that useful info! I checked out those towns and found out they’re on the famous romantic road. I’ll definitely go that route and then maybe I’ll take the autobahn route back to Munich at night hopefully traffic is decreased at night.

A few more questions in addition to my first post, As far as lakes, we are going to be seeing at least a few lakes in Germany and Austria as I mentioned later during this trip, I will be in the Austrian Lake District and will visit atleast one lake there. There are so many that we don’t want to get tired of the lakes. We will be at Zugspitze, which has Eibsee lake directly underneath, some people also recommended Konigsee, we will also be going to Hallstatt. Any you recommend more than others?

After Garmisch I was going to spend a day or two in Innsbruck but I didn’t know Innsbruck is a big city, I would prefer not to stay in a city, because I am already going to be in multiple cities. I would love to stay in a beautiful, picturesque mountain town or village, somewhere scenic waking up to mountains and valleys, something authentic.

Would you describe Garmisch as such a place like I described?

Since I already plan on staying 2 nights in Garmisch-Paartenkirchen using it as a base to explore the area, should I spend the third and fourth nights also in GaPa since I won’t be staying in Innsbruck? Or should I spend those 2 nights in a different location, I would love to stay in the countryside something like I described in my last paragraph. Maybe in Stubaital valley or Mittenwald or anywhere else you recommend? Mittenwald is only 20 minutes from GaPa so maybe I won’t stay there?

also we plan on spending 2 or 3 nights in Salzkammergut / Bad Ischl in addition to the 3 nights in Salzburg. We’ll drive from Salzburg to the Lake District. Will it be a better experience if we stay in Hallstatt or Bad Ischl?

A couple more notes on the autobahn:

You will find traffic lighter after 1800, as trucks need a permit to drive after that time.

If it's raining (or worse) the speed limit is reduced.

Waze is the best app I've found for directions with current road conditions to include police, speeds, and construction as well and accidents.

Garmisch is not a big city. You can easily walk from one end to the other in a couple hours. It is touristy, but i like it.

The Eibsee really isn't much, and unless you can see that it's clear up on the Zugspitze, which you can do from just about anywhere in town, it's not worth going. If you google "alpine panorama cameras" you can get a current time view from the top (mixed in with a lot of others).

Chiemsee is the best of the German lakes down there (my opinion).

We might skip Zugspitze and Eibsee since I’ve already been to Zugspitze and it’s 60 euros per person to go up. Maybe this time we will go to Karwendelspitze which is in Mittenwald, have you been there? It’s half the price. As far as lakes I’ll take your advice and skip Eibsee since we do also plan on going to Chiemsee and renting a boat, also we’re going to so many other lakes including the lakes surrounding Bad Ischl and Hallstatt, we’re staying three days there

Where is the best place to exchange dollar to euro?

Don't exchange cash. Withdraw cash from your own bank account. You will get EUR cash, and the network will take care of the exchange rate at the best possible current rate. Decline any offers to do the transaction in USD, as the exchange rate will be worse.

You are right about the ATM, but the only problem is there are fees every time you take out money, maybe I can just take out however much I think I will need in those few weeks so I don’t have to keep taking it out and adding up fees

These days, credit card usage acceptance has minimized the need for hard currency. Germans still prefer cash, but most will accept credit cards. My solution is to maintain an account at a credit union that does not charge fees. But anything will be cheaper than exchanging physical cash.