Audio Systems: factory bose radio, cadillac seville sls, cadillac seville

Question
i have a 97 cadillac seville sls and the cassette don't work and the factory delco cd changer don't play my burnt CDs so i wanna change my factory radio to a aftermarket radio. my question is can i get a wireharness for the radio that just connect the aftermarket radio to the factory speakers without me changing all of the speakers in the car and also will the system sound play allright with the aftermart with the factory speakers

Answer
yes a radio harness will work and let you keep all the speaker, if you have a regular sound system
if it is premium sound BOSE there is no way to do that all the speakers and wiring will need to be replace,  or you can replace the 12 disc cd changer for a 10 disc mp3 cd changer