Cobalt radio/speakers

2008 cobalt speakers play in back only sometimes and as you ride fronts may come on and then go out again

here is a comment from an internet post that may give you a clue as to how BIG a problem this is and yet CHEV has NO recognition of same. some people have replaced radio and speakers with no result. still no sound. i would guess it's a wiring related issue.

This is messed up! I've been on quite a few forums about this issue and every single one had at least 20-50 if not more people with the exact problem. My car just started with this issue 3 days ago, i went all over creation (including my Chevrolet dealer) and everyone will either say they do not deal with wiring or it will cost $60-$75 to just have it looked at no necessarily going to figure out the problem

just to add info that might clarify things for you. The turn signal clicking noise and the chimes (key in ignition with door open, seltbelt warning, lights on, low fuel, etc.) all come out of the driver's speaker, besides music from the radio. some people haves tested and replaced speakers with success. but that usually just involves the door speakers.