The kind of technology that's there to give you safety warnings should be either be failsafe or not there at all. At the very least the car should warn you that the technology has failed. After years of being accustomed to being advised that your tyre pressures are low, a sudden failure of the warning system could be downright dangerous, so I'm with Maggie on that one. A few years ago the reverse sensors on my three-year-old car failed. I found out when I nearly backed into a wall until someone screamed at me. Ever since then I've never trusted parking sensors.