hoerspielprojekt.de is a website that features audio plays (Hörspiele) for German speakers and learners of all ages, including children (https://www.hoerspielprojekt.de/genre/kinder/). There are audio plays from a variety of genres such as Thriller, Science Fiction, Fantasy, and Drama. So there should be something for everyone.
All of these audio plays are free productions, created by people who are interested in making audio plays. All audio play creators are members of the hoerpielprojekt community. They upload the plays to this website to make them available to the general public.
Right now, there are more than 200 audio plays freely available for download. Some are made by people who are starting to get into the art of making audio-plays, others are made by more seasoned producers and thus of higher quality.
In any way, the audio plays are free and without commercials … and they can help to make a long car ride feel shorter.