South Australia Roadworthy Laws. In South Australia privately owned vehicles do not need to be issued with a road worthy certificate, nor do vehicles transferring registration from another state or vehicle changing ownership.ou can go to your local mechanic to have the defects repaired, however, you will then need to book a time to go to an authorised Police station or DTEI inspection station with the following information 1  : The booking details for the Inspection. 2  Proof that the vehicle is still currently registered.