I have been investigating 'blind spot sensors' , which trigger a light and/or a warning sound when a vehicle is in the 'blind spot'. It is similar to the PDC, except the sensors are installed on the sides of the rear bumper. Has anyone installed these and are they effective? Yes, I am paranoid ... why do you ask??? PS... I am having a trailer hitch installed at MiniFini and will do the installation of the side sensors when the bumper is removed...a real labor saving.