The thing I forgot to mention in my reply about the money above was.... it's a strange coincidence that the only one whose story was materially different from the others was Mngeni and he was arrested first on 16th. So he had the least opportunity to collude with the others over their stories.
Thinking further, all of them (not SD), maybe except Mngeni to begin with, were aware of the amounts of money in the car and each had their own call history on their phones. They didn't really need much else to put the flesh on the bones of a story to implicate Dewani once they knew the game was up - maybe when the police came after Mngeni. If it was a pre planned robbery gone wrong then implicating SD wouldn't have been in their plans, so there would have had to have been some conversations between them.
Thinking further, all of them (not SD), maybe except Mngeni to begin with, were aware of the amounts of money in the car and each had their own call history on their phones. They didn't really need much else to put the flesh on the bones of a story to implicate Dewani once they knew the game was up - maybe when the police came after Mngeni. If it was a pre planned robbery gone wrong then implicating SD wouldn't have been in their plans, so there would have had to have been some conversations between them.