My car came over from Vic, They have to go thru regency, then you transfer the rego to SA.
remove the turbo timer, make sure the pod filter is secure, spray the engine with degreser and pack the zorst with steel wool to muffle it
there is a small time window from getting the car inspected to the last day u can get ur new plates. i got stung on this, and had to take the car back to regency (no inspection, just VIN check)
also keep in mind that when u register it u pay stamp duty, new plates, transfer fee and for the period of time that u register the car for. took me a bit by surprise.
good luck with the purchase