ON OCT. 21, 2016, WHILE BACKING OUT OF A PARKING SPACE, ANOTHER VEHICLE THAT HAD BEEN PARKED BEHIND ME ALSO BACKED UP. OUR TWO VEHICLES COLLIDED - BUMPER-TO-BUMPER, AT A SLOW SPEED (PROBABLY 2-3 MPH). VERY MINOR DAMAGE RESULTED - THE REFLECTOR ON MY REAR BUMPER WAS BROKEN. I AM SURPRISED THAT MY SAFETY WARNING SYSTEM DID NOT ACTIVATE TO ALERT ME TO THE IMPENDING COLLISION. THIS SYSTEM VERY RELIABLY ACTIVATES IF I'M BACKING UP AND CROSS TRAFFIC IS NEAR, OR IF I'M APPROACHING ANOTHER VEHICLE WHILE PARALLEL PARKING. I'M WONDERING IF THIS SYSTEM HAS A "BLIND SPOT" THAT PREVENTED IT FROM WORKING IN THE CASE OF YESTERDAY'S COLLISION.