I believe its an alpine unit, or thats what changer works with it. You need the special interface cable to hook it up ($35+\-) MAKE SURE YOU HAVE YOUR CODE CARD to unlock the unit after power loss! Check this article out at volvospeed and it shows you how to take the headunit out. <A HREF="http://volvospeed.com/Mods/antennasinstall.htm" TARGET=_blank>http://volvospeed.com/Mods/antennasinstall.htm</A> <BR>Good luck,<P>