This thing is annoying. It beeps with every push of the buttons, and the beep is very loud and overpowering, especially through the car speakers. You can turn the beep off, but it involves holding down a button each time power is applied to the device. This is not practical or convenient to ask people to hold down a button while starting the ignition on their car. Very bad design indeed. I owned mine for 30 minutes before returning it because of this obnoxious feature.