I have a hyundai sonata hybrid 2017. the braking system creates a howling sound when the brake is applied. it happened intermittently. i sent my car to the hyundai dealer near me three times. the problem was not resolved. according to the dealer technicians, they were informed by hyundai, the manufacturer that the sound was normal. i am concerned about the safety of driving the car. i hope nhtsa can help me to resolve this issue. thank you.