I recently bought a Factory CD changer on E-bay. But I cannot locate a pre-wire cable behind the grove box? Does anyone know the 07 model come with pre-wire cable?
I talked to the dealer parts department they said is already pre-wire. Please help me and give me instruction. I don't know want to go to dealership to pay HIGH installment fee.
Thank you very much.
P.S. I already search the forum but no luck.

You need the cable shown on the link. You need to remove the pins from the blue adapter and mount them to pins 13 to 20 accordingly on the red connector (also refered to as connector I).

The connector has 3 groups of wires, 2 six wire groups and an 8 wire group. The 8 wire group is where you need to insert the pins.

Here are the pin assignments:
13 - data in
14 - data out
15 - data clock
16 - +12v
17 - ACC
18 - Signal ground
19 - left channel
20 - right channel

If you have SAT radio, you will need to splice 18,19 and 20. Audi controls SAT via CANBUS but shares audio line with external CD changer.<ul><li><a href="http://cgi.ebay.de/AUDI-CD-WECHLSER-6-fach-original-Top-Zustand_W0QQitemZ270103208625QQcategoryZ14259QQrdZ 1QQcmdZViewItem">clicky</a></li></ul>