I installed a Pioneer AVIC-D2 in my 1996 Collector Edition and a Pioneer AVIC-Z2 in my 1993 ZR-1.
The radio bezel does not need to be cut.
The systems work great in the Corvettes.
The AVIC-Z2 has an internal hard drive so you can load you own background screens.
I placed the GPS and XM antennas on the dash. In the ZR-1 the antennas had to be under the coating cutout to get a good signal.
The major electronic stores (Best Buy, Circuit City, Tweeters) would not even try to do the install. I got my local shop (Westminster Speed and Sound, great guys!) to do the installations for me.
When you replace the BOSE head unit you have to decide if you also want to replace the speakers and amps OR install an adapter on the output of the new head unit to provide the proper singal to the amps.
Jim