When i did this i got conflicting info from the DPI, some folks at the call center said NO the car becomes unregistered the moment it hits the WA border(or SA for that matter) unless the owner has a drivers license that represents the state the car is registered in.. A few others said "Yep no problemo you can drive her in WA"

I got the permit to move the unregistered vehicle to be safe it was only like 20 or 30 bux.

If you are shipping the car back and will be there in person id hand the plates back while over there, i returned them to the DPI in WA but getting the rego refunded was a major PITA to do from WA! Faggots at the NSW DPI callcenter didn't want to know me and put me in the too hard basket.