An electronic system to induce the occupants of a vehicle to fasten seat belts is described. The electronic system is configured to determine an alert condition indicating that a seat belt of at least one occupant of the vehicle is not fastened or is not properly fastened. The electronic system is also configured to allow the car radio to operate even when said alert condition is present, and to control the volume of the car radio for as long as said alert condition persists, preventing it from exceeding a low volume level.