that would be on any turn or any movement of the car, his only happens over bumps,no dude its not your bushings. I have the same exact problem. Its your e-brake cable it sits on a little hanger and the black part of the cable wears out til it shows metal. Then the hanger rubs on the cable which causes the squeeking. I just spray sillicon on there for right now until it get warm. Then i can bend the hanger and fix it. So pretty much lube all your e-brake cables on the drivers side. Ull see what im talkin about.