I have a network of ecommerce sites.. All of them sell the same thing but I made one specific for a city. like for NY cars-new-york-1.whatever and have the main one for USA: cars-usa-1.whatever
I want to put all selling cars in the USA site and links in the content of cars-new-york-1.whatever to cars-usa.whatever where the actual car specification is.
Will that affect my seo in cars-new-york-1.whatever? or Google understand that the other one is part of my network (it even have the same cms behind it)
Should I only add like a banner in the NY site to USA site and nothing more not to loose ranking?