One of the big new features of the latest Grand Theft Auto game is the ability to swap between three characters at will. Something you can now do in the last Grand Theft Auto game. Some modders at GTA X Scripting have worked out a way to let you change instantly between GTA IV's three main characters - Niko, Johnny and Luis - in the same way GTA V lets you shift between its three protagonists.
You even get the same "satellite pan" camera effect, showing you that it's a real-time switch.
It's a work-in-progress, but you can download and check it out at the link below.