Today:

Registrations:

Expected output:
{"Audi":{"A3":{"registrations":[{"date":"1\/12\/2012","plate":"CA4444CC"}]}},"Ford":{"Focus":{"registrations":[{"date":"11\/05\/2010","plate":"PB1234AB"},{"date":"1\/12\/2012","plate":"PB1111PB"}]}},"Opel":{"Astra":{"registrations":[{"date":"11\/05\/2020","plate":"CB9999CA","isValid":false}]}}}