It is a 1966 sketch where they are shrunk down and placed in Jackie Gleason's stomach. I'm trying to ID the cart. It's a pretty early 3 wheeler similar to a Marketeer but I don't think it is one. Has a headlight and turn signals. When it tips up you can see it does not have a differential, perhaps it is chain drive to one wheel. The cart appears at 5:00.
https://www.youtube.com/watch?v=ZwFHJlMEVqc
Dennis