how to find out who a car is registered to

Short answer: you generally can’t, at least not legally or easily in Australia.

Owner details are protected by state privacy laws, so the public rego checks and the national PPSR report will give you status, stolen/write-off history, and finance encumbrances—but not the name or address.

If you’ve had a crash or there’s a legitimate legal reason, go through police, your insurer, or your state road authority (e.g., Service NSW, VicRoads, TMR QLD); they can release information only with proper grounds or orders.

Buying or selling? Do a PPSR check with the VIN for peace of mind, and if you simply need to contact the owner about a ding, leave a note and let the grown-ups (insurers) handle the rest.