One place I seem to have false positives is in my drive way, it is on a slight incline and it seems to pick up my mail box. Similar condition at work. I would have to say the RR sensor is a bit sensitive. I checked the arrow indicator is correct. The other time I tend to get false positives is inclement weather. I know the false spots, and I do check for small childred in the vacinity befoe I get in the car, I just look all around when it goes off. False rate of about 5%.