Why put it behind plexiglass, you can't hear it run then.
My friend did a similar thing, but painted scenery on the wall. He left
his open and it sounds great. He put it in the guest bedroom.

wrote:
I just created a new website dedicated to building a display case for
a running model train. The design shows how to build a display case
mounted only six inches below the cieling, that runs around the
parimeter of the room. It works in almost any room, and it doesn't
take up usable space. It is a clasier version than normal, with
plexiglass, crown molding, and a hidden rope light for asthetics.
Anyways, I thought I would share it with the world, and I figured this
was a good place to start. Let me know what you think!

www.ulvr.com/john/train


John