Just had another go at working it out... Checked every wire and all of them were right, 12volt power wire has constant power all the time, and the ignition/accessories wire has power when its meant to, earth is connected, each speaker is working aswell...

Checked the head unit, added/changed some settings. Turned the ignition off, then back on and it worked. Tried it with the glovebox lid closed and it worked. It worked like it should for the next 5 times and then the next go it lost all the settings! :(

I've got no bloody idea why the hell its doing that, I'll just call the auto electrician friends tomorrow and see if they can shed some light on what/why it is happening..

I'm sooooo damn close to having done it all myself, and then have something as little as this hold me up..