Part right, as 'Jack.jlh' said you first go for an ID check, they check numbers, motor/vin/compliance
So depending on some things, such as, when the car was imported, under what rule it came in and what state it was first imported into. They will decide if your off to regency or not because depending on these factors depends on how it was complianced and if SA have different laws it will need to be brought upto SA regulations and fitted with appropriate complaince labels.
A real pain in the ass if you dont know you have to do it, do your research and you will be fine.