I hope they at least have a toggle off switch easy to reach on the dash.  (I doubt the will)

Two things could go wrong without this:
1.  As the car ages and the sensor fails the car because unusable.  Could result in the car becoming a write off unnecessarily.  Example: "We can fix the sensor Sir, it will be $3,400 parts and labor.  But my car is not even worth that."
2.  A bad sensor could keep one from driving away from a situation. 