About 5 or so years ago, I saw on the internet (I believe that it could have been here on OGR) where a modeler placed photographic images of standing passengers from a real subway car into the powered car of their subway train so that the car didn’t look weird compared to the others. It was something like a wrap around the interior box covering the motor.
Does anybody recall this? Maybe said modeler is reading this thread? LOL. 
I’m considering doing this for my subways but need to know what type of material the photos were imprinted on so I’m not having to be concerned about heat generation, flammability, etc.
