There was an awesome blog on home-assistant.io about using an NFC scanner to create a jukebox: https://www.home-assistant.io/blog/2020/09/15/home-assistant-tags/ Since the tags are a bit small for children and i needed a way to identify which tag would trigger which playlist/song i figured lets create a simple shell around it with a picture.

The duplo compatible tractor has been a great print: https://makerworld.com/en/models/388419#profileId-289199 I've printed it multiple times and it is a good hit but unfortunately my kid keeps dropping it. And usually the exhaust and the sides break off. So i've added some reinforcements in the places where it breaks most often and for a week of dropping the print still has not broken yet! Another material than PLA is probably also a good option but this works well enough.