Audio Systems: 99 bmw 528I Adding a additional amp and sub, bmw 528i, ip bus

Question
were do I i find a output to plug into me additional amp.  Is there any way to hook up my Ipod to the factory deck or what ever?

Answer
You need a hi/low interface ,you can plug that into the factory amplifier on the left side of the trunk
also the ip-bus connection are there for the cd changer or ipod
use this interface

http://www.oemautosound.com/pc-354-137-dice-i-bmw-t5v-bmw-1996-2007-to-satellite...