Try Sabi-Sabi or Sabi Sands which both give significant CX discounts on a space available basis. 4 hours or so (dependant on the number of carjackers and police on the take) from JNB.
If you have no success with either, pick up a copy of "Getaway" magazine (available at many book sellers in Central) and take a look at the classifieds section.
FWIW, it's Afrikaans (With a capital "A" and no 'e")...and you do mean South Africans, right?