African Special: The boys travel to Africa with a mission (or two): they must each buy a car – but not a 4x4 – for no more than £1,500. They must then drive the cars they buy across fairly unforgiving terrain in Botswana - including the Makgadikgadi salt pans, raging rivers and game reserves. Game reserves… that’s where big carnivorous animals live, isn’t it? Hmm...