Goto advance auto, CRC Makes a Anti-Squeel spray... and also a thick gel-like one... i recommend the tube (it should be bright orange)... Your brakes are squeeling due to metal on metal contact... Put it on the back side of the pads, and anywhere where metal touches metal or metal touches cast.... This should fix your problem.

 

I would put it in the air (lift or stands) and replicate the issue to see where it is and what it is.

 

Its def. coming from the rear brakes. I had a friend stand next to my rear end last night while I back up and he confirmed.

 

just a stupid thought, but a rock wedged in between the rotor and the dust shield did the same thing to me ones, made a horrible noise. its worth a shot.

 

Well, changed out the rear pads with Duralast cheapys and it hasnt done it since. I think the clouds are finally parting!!!

 

maybe just glazed pads then.