My autistic son loves gauge 0 trains but he also likes to build ones from Lego blocks.
Lego and gauge 0 tracks are incompatible. He always was disappointed when his Lego train creation had to stay on side track while, MHT diesel run with cars on his own track. We finally come with idea to get best of two worlds and glue small lego base plate to a cheap gauge 0 flat car. In other words use a flat car as platform for lego constructions. It's nothing fancy but actually base plate fits and works quite well. My son is happy , his cars and trains can run together on g0 track.
I'm sorry if I put this post into incorrect forum. I couldn't decide which one will fits the best.
I hope you'll fins this idea useful.
Chris.