Some problems understanding the syntax to access two trackers at the same time
I don't know what you call CART (profile, plugin ?)
I think I understood correctly then.
In your template (displaying results from the Magazine tracker) you need add a wikiplugin List to filter all the items from tracker articles with the same magazine number. (we call it plugin list embedding)
You may have bug or other issue there...
I tried, but I'm not sure it is possible to solve this quickly using only the forum.
You may need to hire a consultants or a tiki freelance
to help you with that.