django - how to override admin templates - django-admin

Question

I want to change the way the add new object page looks in the admin page.
I do not want to change the fields but want to arrange the inputs, for example 2 fields on the firt line, then some paragraph then two other fields.
I read about add_form_template and my guess is that this is supposed to allow me to change the template without defining the form.
Here is my attempt which does not show the fields:
Does anyone know whether I need to define the form and pass it in and how?
If I have to pass in the form, then what is add_form_template used for?
from settings import BASE_DIR
import os
#admin.register(Owner)
class OwnerAdmin(admin.ModelAdmin):
add_form_template = os.path.join(BASE_DIR, 'dealer/templates/add_owner.html')
list_display = ('name', 'country', 'city', 'car')
#admin.register(Car)
class CarAdmin(admin.ModelAdmin):
list_display = ('name',)
//----- add_owner.html
{% extends "admin/base.html" %}
{% block content %}
<h1>New Owner</h1>
<form method="POST" class="post-form">{% csrf_token %}
{{ form.as_p }}
<button type="submit" class="save btn btn-default">Create</button>
</form>
{% endblock %}

Answer 1

You don't have to change the admin templates to customize your field's layout. Use fieldsets instead:
# admin.py
#admin.register(Owner)
class OwnerAdmin(admin.ModelAdmin):
# ...
fieldsets = (
(None, {
'fields': (
('name', 'country'),
'city'
)
}),
('Another Fieldset', {
'description': 'Some information to display...',
'fields': (
'car',
),
}),
)