Upvote:4
Yes, rental car companies in Florida are well aware how German drivers licenses look, and used to them (they see probably a hundred every day).
Getting an international drivers license for Florida is a waste of money, as they typically don't know them, and often reject them (they shouldn't - but the checkout clerk does not know them, and what can you do).
[source: I live in Florida, and regulary rent cars with visiting Germans]
Upvote:5
Anecdotally: German license is fine. I have both a German and an international license, and every rental place in every country & state (including Florida) only wanted to see the German one when being offered both. The international one is in my experience quite useless.
Caveat: I haven't done that recently in Florida since I have also a US license now, so I always use that in the US these days.