I'm getting an annoying creaking/squeaking type sound coming from the rear of the vehicle whenever I begin to accelerate from a stop. I'm able to replicate the sound easily by pushing down on the rear bumper. It's kind of a rubber on rubber creaking noise coming from somewhere near the wheels, but the tire isn't hitting the wheel well so I don't think that's the cause. Any ideas? Could it be the suspension? Should I just take it to the dealer?