Interesting because I recall that many years ago, SA was the only state where you were issued with the number/letter combination. You could then buy the plates from the registering authority (don't know what it is called), or you could get them from other places. You could even get them in plastic with fancy gothic characters. I know that at the time, the other states insisted on pressed metal ones and only the ones they issued, so that if the vehicle was involved in a firey crash, they would still be able to identify the vehicle by its registration plates.

Is white on black is the standard colour scheme for SA plates?