Nissan QashQai Forums

In the process of installing a new system in my J11, and in the next few days switching out the speakers, which are running new wires from the amp. For those who have done it already, so I know what to expect, how hard/easy is it to route the wires through the door jams?
Haven't had a look yet, but looking at YouTube, seems it can be a nightmare for some vehicles.

Or do you just use the existing plug with an adapter, and join the new wire on the car end?