Passenger car lighting

[bjpmtravis87]

Just received set of 5 NYC Empire State Express passenger cars from MTH (waited over a year), but, they have really neat lighting.
Use a capacitor to retain power when cars lose power momentarily, and they use two LCDs to light a highly polished plastic bar that runs the length of the car ceiling, which transmits the light then length of the car.
Has anyone done this as a project? It seems like a really great idea, but clearly there has to be some research on the capacitor (type and size), and how to use this "plastic". I know it's not plastic, but I am having a senior moment, and can't remember what this stuff is called.

Anyone done this?

Many thanks.
BT

[bjpmtravis87]

It;s lucite.