I have Brembos cross drilled in front w/ AEM pads for over a year with no problem, due to finances, didn't change rear rotors at the time. Well I finally changed rear rotors to Powerstops cross drilled w/ Axxis pads. A day after I had them installed I started hearing a noise every time I accelerated from a complete stop, like a low pitched squeak once every rotation until i reached high enough speeds that the noise went away or i just couldn't hear it anymore. Brought it back to shop, had both rear calipers replaced, and it is still making the noise. Can anyone help with this problem, I have brought it to 3 shops, and still hear the noise the next day everytime. I think it's sticking but am really not sure, I thought it was on one side now i think it might be the other side. To tell you the truth it's making me crazy. Any help would be greatly appreciated.