Specifically, the Subaru WRX sold in South Africa and Australia is 100% identical. And I mean that South Africa gets the Australian version of the WRX, there's no homologated version for SA.
Well, there is one difference: the service booklet of the South African WRX says the cambelt needs to be replaced every 100 000km (60k miles) whereas the ADM version says every 160 000km (100k miles). The weather and driving conditions between the two countries are virtually identical. The only difference between the two countries is that Australia has 98RON fuel where South Africa has only 95RON. But I can't see how fuel quality could impact timing belt service intervals.
So what gives? Are there good reasons why the same part on the same car, driven in the same conditions needs different service intervals?