I remember watching this film when I was young on Turner Classic Movies (TCM) back when they shared a channel with Cartoon Network. The film was half animation half real action (or whatever it’s called) and was quite old – I’d say about the 70s-80s.
It started in an apartment (possibly american). There was a very young boy around 6-10 years who was alone. I don’t remember how it happened but he somehow got on a magical train that led him out of the apartment and in a surreal fantasy world (where they were now animated). I think there was some wizard who was accompanying him and possibly a dog too. The world was magical. The boy and the other two characters were going through the world in a car (classic model, most likely Duesenberg Model J) dealing with different problems. I think they faced some kind of sludge monster at one point. I don’t remember much more (how it ended, what else did the adventurers do) except that the boy got home in his apartment in the end.
This film has been bugging me lately. I think it was a well recieved film (it was on TCM after all). If anyone remembers it, please help. Thanks!