I recently finished converting an older set of Lionel PRR Baby Madison cars to LED lighting and installed a few passengers in the cars. I did not put any passengers in the Parlor (diner) car, there isn't space for their legs even with severe amputation.
I prefer to have lights in the baggage cars since they came lighted and I have become accustomed to it. I am disappointed that the add-on baggage car for the Santa Fe Super Chief set is not lighted. I might change that if trucks with pickups are available during the next parts sale.
Here are a few pictures.