There are cigarette lighter cameras that will fit on a N scale flatcar or gondola. No, they do not light cigarrettes but sure look like a lighter.
I have ordered one from ebay for about $13.00, free shipping. I have seen a couple videos.
I also have ordered a HD key ring camera that would mount on a HO gondola or flat car. I have seen a couple videos of the key ring HD camera. Both use a Micro SD media card and have a rechargeable battery that gets recharged using the USB to PC cable.
My Nikon and GoPro 900 digital cameras recharge using the USB to Connections also.