It looks like the Tesla playback software for tracks on USB drives does not recognize titles with umlauts. I found this out after looking at my 40 CD set of Bach Cantatas which have lots of umlauts in track titles - and they are all missing in the track lists - although they are there in the drive. I had a similar problem with a piece of playback software in my home system. I don't know what the fix was, but it was done at the software level with an upgrade. I expect the same will be true for Tesla. Priority should be there especially for cars destined for Germany. There may be other problems with non US characters - upside down question marks in Spanish, French letters with different accents, but I haven't tried those.