My daughter owns a 2018 A4 Premium+ with about 40k miles. At its last oil change, the mechanic told her one of the hydraulic engine mounts was leaking. Not badly yet, but on its way. He also said the part was about $400 and the labor $600 to replace it. What happens if she continues to run the vehicle with a failing/failed engine mount and are there any other options to replacing this for a lower cost?