donhalshanks:
Bob, I get your point. The three decks and a lot of hidden track would be difficult. Maybe just the easy to reach main lines.
dhs:
I tried to build a "gleaming pad" for my homebuilt slider cars. It had a large flat stainless-steel washer, glued to a thin pad. It didn't work...somehow, I forgot a certain minor electrical drawback... 
It would have been perfect for a job like this...