I want to clarify the position on this it uses the dedicated CD changer socket, not the auxilliary I actually have installed one and the USB BOX 9702.EZ plugs into the CD Multichanger socket on the back of the RD4 / RT4 head unit found in some Peugeots as well as the C2 C3 C4 and C4 Picasso which it also fits If you have a CD multichanger already installed all you have to do is unplug it and plug the new USB BOX in - it's as simple as that If you don't have a multichanger then it requires the CD changer enabling via a dealer The USB box appears on the display as 'CD4' and with an iPod pluged in you can control all the functions from the steering wheel like volume, skip forward, mute etc. Track display/names is from the radio buttons (or that's what I have found so far but not really had time to play around with it) Unlike the simple cable that goes into the Aux socket and enabled on AUX 1 the USB box has no issue with volume and charges an iPod when connected It will also work if you have navidrive fitted but won't display on the colour screen and should allow you to retain bluetooth as it uses the dedicated CD changer socket, not the auxilliary I will add more detail to the ongoing forum thread c4owners.org but the installation guide / instruction books are in the download section 9702.EZ User Guide Installation guide (Citroen) is in downloads Technical Info section and my own guide is in the Quick Facts section as a 9072.EZ personal fitting guide