I would check the rear bushes in the wishbones, What you could try first on the passenger side first is to get wheel wrench and try and tighten the wheels and see if there is any movement in the suspension arms, then try the drivers side and maybe over tighten one bolt and gently try to slacken off gently to see if there is any movement, or just jack up each wheel individually and hold wheel at quarter to three position and look for movement from side to side, I know the rear bushes on the bottom arm and the void bushes on the trailing arms are very prone to failure. hope this helps.