Parts needed Microtrains couplers #1023 and Microtrains trucks #1010, #1015, or Microtrains BX Express trucks. The Express trucks look like short passenger trucks.
There is no prototype for these passenger car. It is something I wanted for myself. If I am going to make something for myself I can make kits out of it.
They track well as they are bottom heavy. The side doors are separate parts. They can be positioned where you want them.