To just add some more info for Boxster installations (actually for CDR-220 installations):
Check out the Becker web page, they make the CDR-220. go to http://www.beckerautosound.com and
follow the links to the Becker Board. Some of the best posts are gone, however. Bottom line is that
you can use the CDR-220 CD changer input as an auxiliary input. This lets you keep the head unit
as the primary control point for your Empeg.

You can call (in the US) 888-423-3537,
ask for Burl x209, and ask for the audio cable for phone and aux input, and also ask for the radio removal
tools. The CDR-220 connector pinout is at http://www.beckerautosound.com/porscheconn.html .
The CD or Aux audio inputs are in connector box C3 (not shown in the diagram, but retrieved from
board messages):
pin 18 Ground
pin 19 Left channel audio
pin 20 Right channel Audio
pin 8 12V
pin 9 ground
and you will need to turn on Auxiliary mode in the user menu.

Please note that I am still waiting in the queue, and I havn't installed
anything yet, but I have gathered this info in preparation, so am posting
for others.

-gbeck

Still waiting #145xx.....