Hacking the Django admin is both bad form and, at times, a great time saver. As this post shows, subclassing admin.ModelAdmin can get you very far, specially if (unlike in that post), you go beyond save_model and start wrapping and replacing other methods of the base class (e.g., you can wrap form generation to preload useful dynamic values — and why the hell don’t default callables take arguments?). The obvious use case is creatively restricting what admin users can do (yes, I know, not what the admin is there for… or so we are told), but you can do very arbitrarily funny things.