class CommonCarInfo(CommonInfo):
    car = models.ForeignKey('main.Car', on_delete=models.SET_NULL, null=True)
    supplier = models.ForeignKey('supplier.Supplier', on_delete=models.SET_NULL, null=True)
    price = models.DecimalField(decimal_places=2, max_digits=10,
                                validators=[MinValueValidator(limit_value=1.00)], null=True)

    class Meta:
        abstract = True

class AutohouseCar(CommonCarInfo):
    autohouse = models.ForeignKey(Autohouse, on_delete=models.SET_NULL, null=True)
    amount = models.PositiveSmallIntegerField(default=1)

Пытаюсь достучаться до car