Translation:There are no cars in the department store.
How would you say there are NOT cars in the department stores. instead of There are NO cars in the department store. Is there a difference?
"There are not cars in the department stores." does not sound correct to me in English.
At least not unless you are setting up a contrast, e.g. "There are not cars in the department stores, but trains." (Which I think would be Az áruházban nem autók vannak, hanem vonatok.)
Department store is such an old fashioned way of referring to a shop, it might as well be a practical flaw in a language exam. "Shop" is a beautiful word that covers üzlet, bolt and aruhaz at the same time.
In American English, at least, we use store more often than shop. A shop tends to be a smaller establishment with specialized items, while stores are bigger with a variety of items in larger quantities.
they need to get rid of this "department store" thing already, at least not to count it as a mistake
In a previous exercise was "nincs piros alma az áruházban", and in the comments they said, that plural isn't needed in such structures. However, here i see "nincsenek autók" - why plural?