Nice one super, just bear in mind with the remote control one the box needs line of sight to the remote as it will be an infra-red (IR) signal which operates it. I know you probably know that, but just in case 
Of course if you can get away with a big control box stashed in the train somewhere maybe you should be looking at EL strips instead of LED's? They can be cut to length and provide a constant strip of light similar to a flourescent tube in comparison to a bunch of bulbs...
Also meant to say I found this article on Reed Switches don't know if this is of help, but you could potentially use one of these to replace a physical switch and then find somewhere to place a magnet on the car to turn the lights on (maybe on the underside of the car).
Of course if you can get away with a big control box stashed in the train somewhere maybe you should be looking at EL strips instead of LED's? They can be cut to length and provide a constant strip of light similar to a flourescent tube in comparison to a bunch of bulbs...
Also meant to say I found this article on Reed Switches don't know if this is of help, but you could potentially use one of these to replace a physical switch and then find somewhere to place a magnet on the car to turn the lights on (maybe on the underside of the car).
Happily collecting things all my life... 
(This post was last modified: 12-07-2021, 07:35 AM by Super.)