Our Blind Spot Sensor System mounts sensors on either side of the vehicle to alert you of vehicles in your side blind spots. One of the hardest to areas to see around your vehicle while driving is the area slightly behind and to the side of the vehicle. This is precisely where these sensors mount to alert you of vehicles that would otherwise be hard to see. While there will always be visual alerts, audio warnings will only trigger if the turn signals are on. The visual alert for this system is strategically placed in the "A" pillar in the vehicle to be easily seen by the driver. ***Note: SENSORS CANNOT INSTALLED WITH A METAL BUMPER.