I have a 2005 with factory satnav and CD changer. The satnav and changer are faulty and not economical to repair. I am looking at more up to date head units, but I understand that I will need an extension lead to run from the front to the back of the car. How easy is it to fit? What is involved? Is there a thread on it?

I am pretty good with things like car stereos but if it is a mission to fit I might just pay to get it installed.

I tried google but can't find anything.

Thanks

Rich