What i have noticed is the bar graph display isnt all that accurate, when its fully black i.e as far as its concerned im as close as possible to an object im trying to avoid when parking, when i stop the car and get out and have a look as to how far away it is its normally at least a foot and a half away from the car meaning i often have to move the car forward/back a bit to get it parked properly in car parks, often i just ignore them to be honest!!