I think the DSI bit refers to the engine type . In the european specification it was available in 4 trim levels, S , SE ,SE sport and sport. All European trim levels had heated mirrors.
The main difference is SE had air conditioning , and electric rear windows, the S did not. But as you are in South Africa all bets are off . The south african specification trim levels may be completely different, missing some features, or adding others. Even the lowest trim level may have had airconditioning, while none may have had heated mirrors etc. The trim level may have a different name.
As Olduser says the main difference is likely to be whether the replacment mirror is heated or not. As most Jazz came with heated mirrors its likely that most replacment spare parts will have a heating element stuck on the back of the glass, whether it needs it or not. It doesnt add much to the cost and saves having to stock both types. If your car door is not wired for a heated mirror its not really worth paying an electrician to wire it up. You didnt have a heated mirror in the first place. If the replacment mirror is not the heated type I dont think an electrican could make it so, and do you really need it to be heated?
