"Auf Wiedersehen" is the correct original title of this movie as you can see here and here.

Well, how about you look at original source material, like here. Also, I can recommend the entry at the German Film Institute, here.

Look at the on-screen title in this trailer.

@fisonic wrote:

Well, how about you look at original source material, like here.
Also, I can recommend the entry at the German Film Institute, here.

This movie is a case of both titles in use at the same time and we have to pick one of those 2 for TMDb as the original title!

For example, look at the link that you mention (filmportal), and click on "Title" in the column in the middle -> you can read:

Originaltitel (DE) Auf Wiedersehn
Schreibvariante Auf Wiedersehen
Arbeitstitel Drei gegen Amerika

Filmportal decided to take "Auf Wiedersehn" as original title. But then click on the links in the right column that begin with "Tagesbericht" - for example, this one:

https://www.filmportal.de/sites/default/files/6B8DF20A82ED4A958B38FB27AF740D11_F015921_ABA_123_TB_003.pdf

You can see the title is "Auf Wiedersehen" during the time of production. As far as I checked, all those original/official documents during production use this title. But then - for reasons I can't find out - the title was changed to "Auf Wiedersehn" for all the posters and all the other publicity for the theatrical release -> there are tons of other "merchandise" articles available online. And then, another source, filmdienst, mentions that "Drei gegen Amerika" was the title of the film when broadcast on tv ("Fernsehtitel") - not the working title ("Arbeitstitel") as claimed by filmportal.

As you can see -> big confusion!

So, how should we decide? The Contribution Bible suggests here:

"When the promotional material use slightly different titles (e.g. Twelve Monkeys vs 12 Monkeys), we try to use the title as it is written in the original on-screen opening credits."

And here is the title card at 0:14 min on YouTube:

https://www.youtube.com/watch?v=JyHyVF5TSCs

That's why - in my opinion - we should use "Auf Wiedersehen" here on TMDb as the original title.

Thank you for the link, superboy97, and thank you for the explanation, janar! I totally agree the on-film title should have priority. Good work!