By the way, here is a greeting-card-style sound module with user-loadable sound-file input: bigDAWGS Greetings.
The subway cars you're talking about are the R-32 class, and from the photo you posted, appear to be the 'dealer appreciation set' with the graffiti that terminated the MTA's agreement with MTH.
The YouTube video of the mechanized doors may have been accomplished using an RC servo.
The difficulty with motorizing the R32 doors is getting controlled mechanical force to the door panels. The way they were designed is to use a lever to move a rack containing the door panels on one side of each door opening, and small gears drive another rack in the opposite direction with the doors on the other side. The mechanism is subject to coming apart when lifting the body shells because the retaining plates keeping the gears in place is on friction-fit pins rather than being screwed down. If I recall correctly, the addition of open-able doors was a late addition to the feature set, and may not have been extensively planned out at the time the cars were announced. You can see that it was not repeated on other Premier-class subway cars (R-1, R-40)
The Lionel Acela uses slot-car motors equipped with long screw drives at each door panel to open and close them.
Before anyone mentions the Coors Light set, it should be mentioned that the feature isn't considered reliable beyond four cars from the locomotive. I added two extra cars to mine before the tail car came out, and only infrequently would any more than the first 4 cars respond to the door signals.
BTW, if you're looking to re-create NYCTA tunnel lighting, you should probably know that the prototype is using light bulbs (mostly compact-fluorescent, but the most recent installations may be using LED bulbs) that point down at the trackbed, with shields on the side facing oncoming traffic, so the lights don't glare in the faces of train operators. In this application, rather than the subminiature LED's in the photo linked a number of posts ago, a more conventional 3mm LED pointed down, with chopped-up silver-painted straws cut in half lengthwise glued to one side, would look closest to the real thing.
---PCJ
