2002 Bonny stereo

I have been trying to install an aftermarket stereo and CD in this car and have found it is virtually impossible. This has the Data 2 system that uses the radio for certain functions of the onboard computer. It also connects itself when you slide it into the dash. Does anyone know of any way to connect an aftermarket radio to one of these beasts? I have not been able to find any aftermarket harnesses or kits that will work with this.

http://images.cardomain.com/products/sco/SCOGM07B.jpg
http://www.sounddomain.com/shop/item.pl?sku=SCOGM07B&vq_id=none

There is a relocation harness that has recently been developed for the 2000+ Bonnevilles that will allow you to retain the chimes and other things lost when installing an aftermarket unit. I believe it relocates the factory unit to the trunk. I dont have any links on it so you'll have to do some Google searching.