title: Django InlineAdmin for ManyToMany field which doesn't have an explicitly named through
body: <p>I have two models, with <code>ManyToMany</code> relationships:</p>
  
  <p><code>App1</code>:</p>
  
  <pre><code>class Foo:
      fld = models.CharField(null=True, blank=True)
  </code></pre>
  
  <p><code>App2</code>:</p>
  
  <pre><code>class Bar:
      foos = models.ManyToManyField(Foo, blank=True)
  </code></pre>
  
  <p>Now, on the admin view of <code>Bar</code>, I'd like to present <code>foos</code>. I cannot simply list <code>foos</code> as a ManyToMany field, I get an error message.</p>
  
  <p>So I try to do:</p>
  
  <pre><code>class BarFooInline(admin.TabularInline):
      model = Bar_foos
  
  class BarAdmin(admin.ModelAdmin):
      model = Bar
      inlines = [BarFooInline, ]
  
  admin.site.register(Bar, BarAdmin)
  </code></pre>
  
  <p>I got the name <code>Bar_foos</code> by look into the Meta of Bar. <code>Bar.foos.through</code> yields that as a proper <code>models.Bar_foos</code>. But since I didn't explicitly name the through, it's not really in the <code>models.py</code>, so I cannot import that. What should I do?</p>
  
  <p>I don't want to create a through now, because I already have a whole bunch of association information in the table, and I have a feeling that wouldn't be magically data migrated into the newly named association entity's table (<a href="https://mounirmesselmeni.github.io/2013/07/28/migrate-django-manytomany-field-to-manytomany-through-with-south/" rel="nofollow">https://mounirmesselmeni.github.io/2013/07/28/migrate-django-manytomany-field-to-manytomany-through-with-south/</a>).</p>
  
  <p>Also, I cannot move the <code>ManyToMany</code> field from <code>App2</code> to <code>App1</code>.</p>