Car rental In Germany

try www.hertz.de they have a very good reputation

Dropping off a car in another city should work, dropping it off in another country is usually more complicated and more expensive. Some rental companies have restrictions on the countries you're allowed to enter, usually Eastern European ones. Don't think the Czech Republik is one of them. You need to check that before you finalize the booking.

Once you enter Austria with your car, you will need to have a toll sticker to drive on the highways there.

The market leader and most reliable one is Sixt, followed by Europcar. Then Hertz, Avis, Budget and National are also available and have locations all over Europe as well. You can drop off your car in any other German city at no additonal charge. And the name of the city is Frankfurt and not Frankfort. ;-) A Furt is a passage where you can cross water (e.g. where you can cross a river). A Fort is something like a castle...

you need a car vignette to travel in Austria, it is good for 10 days, it cost around 7.7euros, you can buy it at any gas station or convinience store after you get in Austria.

You'll also need an orange safety vest to keep in your car in Austria. The rental company may provide one, or you can pick one up in any gas station.

In addition to those mentioned check with gemut.com and autoeurope for rate comparisons. Both reputable agencies. Also, be aware of the cdw requirements. If you have your own through your cc make sure you decline on the contract when you sign. If you go that route call your cc company and make sure they do in fact cover your cdw. Also, get your IDP through your local AAA office.

What is a cdw?

CDW: Collision damage waiver; simply type "define: cdw" into a google search field (without the ")...