Funny you should say that - I am considered very tech savvy. I am often the go-to guy for installing speakers, HUs and other toys
( I have managed some pretty neat mods on my smart roadster, which was once reckoned to be the most modded in the UK)
Is the SatNav headunit on the 308 exactly the same as the RCZ unit? The French are extremely fond of minimizing their Stock inventory
so it would not surprise me - and I can imagine a scrapyard dealer being happy to sell HU and cable but less enthusiastic about just the cable...
Does it require a significant dismantling of the dashboard? I am not looking forward to the 'learning curve' of which parts have to come off
in which order, how you gain access to that last stubborn torx screw, etc ,etc.
So having a go- to guy would save masses of time and swearing etc and would be outstanding
If you have the NG4 as in the pictures posted in this thread below i.e the head unit with a 1-9 keyboard on the right hand side.
I asked the dealer if he had any sat nav cables in stock and he brought out a box for me to look through and I found it marked up as off a 308. I have since seen the cables on Ebay !!! £30
The surround of the screen just unclips with a trim tool lift up from the dash Then you will see four Torx screws two at the front and two at the back take them out and the screen will lift up.
Once you have it out the screen is in two halfs and again unclips with a trim tool. Inside the screen you will see a chrome backplate held in by four tiny torx screws.
Take them out and lift the back plate now you can see the board in the screen. Right in the middle of the board there is large metal cable connector with the video lead plugged into it. un clip the video lead and feed it through the hole in the right hand hinge. The hinge has a red clip to pull out allowing the lead to pass through. You may see some cable ties holding the cable around the hinge cut all them off and dont re fit them on the new cable. Can get tricky here as the metal plug end needs to be removed just leaving the plastic plug end. This is because of the bend in it is not the same as the OEM cable the 308 cable has this slight difference but its not difficlt to get the metal plug case off the lead. You need to do this at both ends of the cable. Once you have taken the metal plug surround off both ends feed the cable through the hinge and plug it into the screen. Feed the other end through the hinge and down inside the dash.
Ok thats the screen side of the cable now you have to take the head unit out with four radio/headunit removal tools like four short knifes that fit in to the slots on the front of the head unit. Pull the head unit out using the removal tools and you will see the video cable on the right hand side at the back of the headunit. You can easily id the cable because it has a metal plug end. Pull that out and plug in the new cable. See pictures below I have included the cable you need to look for. Good luck.