title: Django lookup multiple models reusing querysets
body: <p>Let's say I want to get a list of houses where the owner's car has a seat that's red.</p>
  
  <p>I could do it like this:</p>
  
  <pre><code>queryset.filter(owner__cars__seats__color='red')
  </code></pre>
  
  <p>However, I would like to reuse the filter of getting cars that have a red seat, so I have a custom Queryset on Cars.</p>
  
  <pre><code>class CarsQuerySet(models.QuerySet):
      def with_red_seats(self):
           return self.filter(seats__color='red')
  </code></pre>
  
  <p>Is there a way to do reuse the "with_red_seats" filter on the first query?</p>
  
  <p>Something like this, which obiously doesn't work:</p>
  
  <pre><code>queryset.filter(owner__cars__with_red_seats)
  </code></pre>