Seeing as Alber2 didn't explain his method: here is my method that i created to import the map my self, it seems to work perfect with the exception of the fact that instanced objects like trashcans, streetlights, fire hydrants, etc are all unique but that can be fixed manually. I don't know if it's %100 same as albers but i guess it's pretty close because it looks like he used 3DRipper as the texture names are all memory addresses which is something 3DRipper does.
1) Install Mafia (duh
2) Download and run Mafia World Editor, i used the current latest version 0.4 Download it here
3) Download and run 3DRipperDX, i used v1.8 because that was the one on my pc, dunno how new it is.
4) Use 3DRipperDX to run the Mafia World Editors 'Editor.exe' and load a mission from the dropdown menu, 'missions\freeride' is the whole city (with the exception of specific interiors and a couple places like the tutorial location as Alber mentioned i think)
5) Once the map has loaded 3dripper will start dumping some of the textures straight away so may slow down the program a bit, to load all objects in the scene so the ripper can rip them properly set the Camera Far distance in the Settings tab on the right side to 99999 and its important do not move the camera to pan around the scene if you want to rip the map with the rotations correct and not f*cked
6) There are XYZ coordinates boxes in the center of the main window, just below the 3d view, set them to 0, 0, -9000, as Mafia seems to use a Y-up axis then this will move the camera all the way to the side so every object renders (the tool seems to do some culling so the whole map wont rip unless it's visible/rendered in the 3d view so putting the camera all the way away solves this because nothing gets culled. Setting the camera to this coordinate will freeze the program for a little while because 3DRipper is now ripping every texture, for example freeroam uses 1133 textures.
7) Wait for it to rip all the textures, you'll know it's done when the textures folder you defined in 3DRipper before running the world tool will be full and won't start adding more textures.
8) Rip! (f12 i think), this will rip the 3d mesh
9) Import the .3dr file using 3drippers 3dsmax plugin, use the "recommended values" dropdown menu so the map isn't streched.
I may use this method to help John (GamingDamned) with his GTAIV version of Mafia map, he doesn't know how to rip the map himself (and i doubt he would get the hang of this tutorial) so i might just rip the special interiors and send him the .max and textures of them.