We thoroughly test and develop our products with you in mind. You cannot just place a sheet of metal underneath the car and not expect to have noise and vibrations. We’ve considered almost every variable such as the movement of the converter, exhaust system, engine, and angles and planes of mounting points, in our design. We use spacers and noise dampeners to ensure that the only time you know the shield is on is if you look below the vehicle. The Prius Liftback, Prius C, and Prius V specifically use spacers and dampeners.