I called up Porsche today for some info, and what they told me was:
1) there is a special tool needed to get the old stereo out
and
2) Taking out the factory stereo can and probably will mess with the alarm system
Could I get some verification if this is true? If so could someone give me a bit of detail on what to do? I decided to get a nice Sony unit:
http://www.walmart.com/ip/Sony-MEX-BT38UW-Xplod-Bluetooth-CD-Receiver/14262179
Comes with Ipod integration and bluetooth which is handy with a manual car, so I'm happy with that.