Django custom RelatedManager with ManyToManyField for multi-record inheritance

[Dr. Sultan Alotaibi]

I have the following object structure:

class Car(models.Model):
    name = models.CharField(max_length=16)

class Person(models.Model):
    name = models.CharField(max_length=32)
    cars = models.ManyToManyField(Car, through='Relationship')
    parent = models.ForeignKey('self', null=True, blank=True, related_name='childrens')

class Relationship(models.Model):
    car = models.ForeignKey(Car)
    person = models.ForeignKey(Person)
    love = models.BooleanField(_('love status'), default=True, db_index=True)

The logic is of the models is:

• A Person may be have another Person (children, for instance-ForeignKey on 'self').
• A cars (related manager) should return a cars of the current related person + a cars, that his father (if exists) have (inheritance).
• A children can't add to self a car, that his father already have (inheritance).
• A relationship_set manager should work by the same logic of cars manager (if a father loves a car, then a children should love it too.

This logic looks like inheritance. I can't implement this logic by Multi-table inheritance, because achildren may have other children. Maybe there is some ideas like multi-record inheritance?