False sense of security

You know those vehicles that have back up sensors that tell you when you are going to run into something?  Yeah, I have one of those.  I think those back up sensors have lulled me into a false sense of security.   You see, these sensors are only work when the object is is direct line with the sensor and is tall enough for the sensor to detect.
So today, my son left his brother's scooter behind the Tahoe.  But the handle was resting on the side of the vehicle.  I failed to check behind the Tahoe because I only had one child at home and I had followed him around the front of the vehicle so I would know where he is.   Okay, fast forward.  Child buckled in, check.  Garage door open, check.  I start to back up, until I feel the Tahoe get stuck on something and hear a sickening crack!  Ugh.  I knew it was bound to happen.  You guessed it, the scooter is no longer in a workable condition.  I threw it out of my way and went on my merry way to pick up my other son from preschool.   He still hasn't figured out his scooter is broken and I'm thinking I don't want to tell him.   I'm not ready for the breakdown that is sure to happen as he is in a very good mood right now. 
So, in light of this happening, I realized that these back up sensors have become a bad thing in a way.  I find that, like today, I do not always check behind me, especially when backing out of my own garage/driveway.  After all, the sensors should warn me if I'm going to run into a child, right?  Maybe not.  What if there is a child sitting in my driveway, or in my garage, right behind my vehice?  What if a child is not tall enough to be detected by the sensors?   It is no wonder so many children get run over in their own driveways.  Not only are children careless around vehicles, there are parents, me included, that have been lulled into a false sense of security.  With all of the etra security measures included with vehicles nowadays, more people, such as me, are less vigilant about checking the perimeter and  trusting that the vehicle safety equipment will do our job for us. 
This is a reminder to me that I need to be more vigilant.  I usually know where my own children are, but I do not want the fate of my son's scooter to inadvertently happen to a child.