Apologies if this is a stupid question, but does the plug thing from my aux cable go into the black port on the left hand side if the MFD2 unit? it seems to be the same shape but there's a little plastic clippy thing making me wonder if I shouldn't force it...

I've taken pics but photobucket is playing up

The aux lead plugs into the socket inside the jumbo box.

 

I'm unsure of the one that you're referring to though.

I don't have an aux input so I'm trying to install one of these

http://www.ebay.co.uk/itm/281043861022

Socket must be fitted (or replace existing) blue socket

 

 

Octavia 1Z came with a 12 pin socket, your image seems to be for another radio

I had one of these

and I plugged it into the black port on the left of this pic

It now plays audio from my phone, including phone calls, through the car speakers when I plug the aux thing into the headphone port on my phone. I have to select "aux" and "av" in order for it to work. Does this sound like I've done it right?

This is my stereo unit

The large black connector deals with audio+video, and Reverse Camera, not the Aux input.

 

The pin assignments for the blue connector are:

1 –  AUX signal input, left
2 –  AUX signal earth
3 –  CD changer, audio signal earth
4 –  CD changer, voltage supply, positive, terminal 30, contact continuous load greater than 1 A, temporary peak load 5 A
5 –  Not assigned
6 –  CD changer, DATA OUT
7 –  AUX signal input, right
8 –  CD changer, left audio channel, CD/L
9 –  CD changer, right audio channel, CD/R
10 –  CD changer, control line, switched positive
11 –  CD changer, DATA IN
12 –  CD changer, CLOCK (internal check protocol for data flow monitoring)

 

 

So 1, 2 & 7 are the ones you'll need to be looking at.

Thanks for that :-)

So if I've plugged it into the audio + video bit and it works for audio (which is all I want at the minute), is there any harm in leaving it like that for now?

Yes that's correct. I have my x-car link plugged in through the main connector (bluetooth) and I have the Aux cable as you have also. Select aux on the hu and then av.