FWIW, several months ago I contacted Duragloss and asked them about topping 105 with a carnauba wax. In reply they said that it would compromise the durability of 105.
I do not know which is more durable DG 105 or Collinite 845. My guess is that 105 would have the edge, just based on what I have read; but that is just a guess. Does anyone have any experience with the two products that would help on the durability question?