Python 如何将可自定义查询集用作表单中的下拉选项？

理想情况下是这样的：

forms.py

class SelectCar(Form):
    def __init__(self, custom_queryset):
        choices = custom_queryset
        self.fields['choices'] = forms.ModelMultipleChoiceField(choices=choices)

def index(request):
    queryset = Car.objects.filter(brand=brand).all()
    form = SelectCar(queryset)
    context['form'] = form
    return render(request, 'form.html', context)

views.py

class SelectCar(Form):
    def __init__(self, custom_queryset):
        choices = custom_queryset
        self.fields['choices'] = forms.ModelMultipleChoiceField(choices=choices)

def index(request):
    queryset = Car.objects.filter(brand=brand).all()
    form = SelectCar(queryset)
    context['form'] = form
    return render(request, 'form.html', context)

此处的

queryset

依赖于其他对象作为下拉列表中应显示内容的过滤器。有没有一种方法可以干净利落地做到这一点