Hello,
(I got your PM also) - Did you look at my Wiki page here....
http://wiki.phathack.com/VW_Phatbox_to_Volvo_Transplant_%28How_To%29This tells you pretty much everything that there is to know about putting a VW / Audi box into a Volvo (and so long as the the V70 that you have has a compatible head unit - HU-803 / HU-850 types are OK) then this should be possible. You cannot use the Audi cable, so I suggest you keep it (if you ever change to an Audi) or you sell it.
Does your V70 have navigation or a CD changer in the back? If so, then you will also have the wiring from the head unit that you need to connect to. Some vehicles have this wiring (known as Navigation Preparation) already included, but you will need to check. If you don't have this, then you need to ask your Volvo dealer about it.
Note that if you have a 10-CD changer then you have to remove this so that you can use the Phatbox. The Volvo/Phatnoise system uses the CD changer control system to access the Phatbox, so you cannot have both installed at the same time.
I hope this is helpful to you.
I know of at least one person who has followed these instructions and now has a box working in his V70, so I wish you good luck.
Les.
