Placement of the whistle is extremely critical. The sound comes out the back of the whistle not the front. If you place it on your bumper and your car body is behind it will not work. I never hit a deer in a vehicle with a whistle. Here is a tidbit to think about. I mounted a whistle on top of my Isuzu Trooper in front of luggage rack. When living in Texas I would go to work on this very long and straight F&M (country) road. There was usually a large flock of sheep at one section of this highway. When I topped this hill approximately 1 mile from them, they would run to the other side of the field, but only when I drove the vehicle with the whistle.
