Dont be surprised if the aftermarket radio doesnt sound good with your Oem amp and speakers .
I ended replacing all cause the sound quality wasnt right and a static noise kind was always on due to the lack of adjustment on the Amp
I would start replacing radio and check how it performs .

Btw if you decide t replace whole system then ByeBye onstar and chimes ... steering wheel still works with the adaptor .
belive it or not the whole audio system replacements is a DiY . and not hard

 

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