Well, to be frank, the ppl who dl from here are probably not using 'installation' in that they're running the *.exe because if you do that and the connected unit is not one that's entitled to the update, the self-extracting exe will only go so far before it realises the wrong unit is connected:

1p4o 1np3

So if you have the *.exe, you simply extract it manually to find the MapData folder and in it the locked gmapprom.img together with ancillary files needed for the particular unit depending on the 'type'. The advantage in doing that is not only do you get the extra files, but you can unlock the map yourself so you know it's done correctly.