This guide is not going to show you all the locations. They are already shown on the map, so no need for that. Press the track pad on your controller to see the map.
This guide is to point out that some of the legends on the map for the hotspots appear underneath tasks. This becomes a complete pain to find the final few if you have not done loads of tasks yet. I got to 99/100 and scanned over the map about 5 or 6 times on different zoom levels before I found the last one.
If you press UP on dpad and browse to the Hotspots section, then you will see a list of the closest ones. Some people have had luck with this function by using Fast Travel to each of their hideouts (the fast forward symbols on your map) and checking here to see if it shows any that they haven't come across yet