Safety or Superstition???

For most part of my childhood and I guess even now I have witnessed this sight so many times. People tying a lemon and few red chillies to their transports as a mark of safety (supposed to be considered auspicious). I have never understood its significance...or rather, have never tried to understand its significance. It is out of my space of logic to understand how exactly is this combination so auspicious or for that matter how does it even denote safety. But then, I think deep down all of us are like that, we all have our own fears and inhibitions. And at such times, belief belies even the strongest of arguments.