First, I don't speak/understand any so-called agglutinative languages, like Turkish. I also don't know German.
I understand there's no good definition for the concept of "word", which could apply to all languages. But for the sake of this questions let's assume we define word as something independent of writing.
I am always a bit skeptical about some languages being able to construct very long words. This skepticism come from the fact that I've seen such claims about languages I know well. For example: many times I have heard and read info like "English words are much longer than Chinese and Vietnamese words" while in my opinion these claims are based on the biased bracketing of the syllables and morphemes. For example a word like: "unbreakable" translates to Vietnamese "không thể phá vỡ", for some reason "không thể phá vỡ" is never regarded as a word neither by Vietnamese nor by English speakers. I would not consider "unbreakable" a single word any more than "không thể phá vỡ".
Now I think similar "tricks" are made with German and Turkish long words. That is I believe that the Turkish "muvaffakiyetsizleştiricileştiriveremeyebileceklerimizdenmişsinizcesine" and the German "Kraftfahrzeug-Haftpflichtversicherung" are just bunches of words. It just happens that spaces are not put inside these bunches.
The only doubt I have about my example is that "không" is actually a single word that can be uttered alone, while the English prefix "un" is not.
Could anyone break down these long words to shorter words to show it's possible or contradict my intuition-based claims otherwise?