Blueprinting cargo wagons with filters?

[Eddie the Jedi]

I can't figure out how to do this, is that because there is no way or because I'm stupid? If the former, is there a mod that wiuld help?

[impetus maximus]

you can't blueprint locomotives or cargo wagons. you can copy and paste settings with shift+right click (copy) and shift+left click (paste) from one cargo wagon to another.