I was looking for something to do with small portions of filament that are left in samples after I'm done printing the obligatory benchy. My 2 year-old son likes playing with cars and has some wooden tracks that can be built out of small segments. I decided to design these cars so the would be sized appropriately for those tracks. The wheels are printed separately and simply snap on, but are difficult to remove once attached. These are intended to be sturdy and are unlikely to be broken by a small child, although an adult stepping on one could quite possibly break an axle. I would described the general styling as low-poly, although the axles and wheels have a lot of polygons, so they aren't really low-poly. There are currently two style - a basic car and a pickup truck.
Some compatible projects:
https://www.printables.com/model/224234-uberbloxmini-tracks
https://www.printables.com/model/117903-extended-set-of-wooden-train-track-with-50-unique-
The author hasn't provided the model origin yet.