Right, on PC now...
You need a 6 lenghts of heavyish guage wire, I had some speaker cable that came with surround sound system so I used that.
Colour code the ends of each wire to make it easier to identify them, then run them under the rear door cards, underneath the base of the seat, around the base's hinge, then along the lower part of the rear trim, underneath the door sill trim, then up around the weather seal, behind the glovebox and in through the small gap to the back of Headunit.
orange & green - splice into rear speaker
orange & black - splice into rear speaker
blue & red - pin 2 in audio iso harness
Blue & yellow - pin 1 in audio iso harness
Black - earth - locate nearest earth, probably rear light cluster
Grey - auto antenna, pin 5 in power iso harness
Red & white - Power - splice into igintion switched wire in power iso, or into main power cable,
Here is the wiring diagram that I used to figure out the wires,
[url]https://www.fiatforum.com/gallery/data/2771/medium/WDPuntoMk2-10.jpg[/url]