Postgres JSONB - Flatten nested objects and groupings
You need to unnest twice:
select x.m -&gt;&gt; 'manufacturer' as manufacturer,
       x.m -&gt;&gt; 'address' as address,
       x.m -&gt;&gt; 'contact' as contact,
       m.model -&gt;&gt; 'model' as model,
       (m.model -&gt;&gt; 'starting_price')::int as starting_price
from the_table t
  cross join jsonb_array_elements(t.models -&gt; 'cars') as x(m)
  cross join jsonb_array_elements(x.m -&gt; 'models') as m(model)

Suppressing repeating values is better done when you display the data in your application, not in SQL.
Online example