Hyundai Accent won't stop squeaking

I'm having a problem with my 2001 Hyundai Accent. After driving for awhile, usually 15-20 minutes, from the back right the car makes a rotational squeaking sound only while driving. When I press the brake, it completely stops. This seems to only happen when my steering wheel is slightly left. It doesn't happen all the time, but sometimes loud and sporadically, and other times it completely goes away.

I've gotten the brakes replaced two times this year in the back (drum brakes), and three sets of brake pads. They seem to keep getting worn down, or mechanics are cheating me. I also don't know if the brake drum has a piece of metal stuck in it or what.

The car was in an accident where it was hit on the right door, but my last mechanic said there was no way it could have unaligned the car.

Does anyone recognize this problem? I'm getting desperate and want my car to work. It is still under warranty but since it still drives the dealership won't help me. Thanks!