Do not leave your music system and valuables in the car. Regarding original car documents, it is advisable not to leave them in the car, however, Check with your local Traffic Police if it is permitted to keep attested copies of the registration certificate in the car instead of originals.
An expensive Music system, mobile phone or Valuables in the car are sure bait for criminals.
Wearing heavy jewelery with windows rolled down is another invitation to snatchers.
Never forget to put the external steering lock even if you are leaving the vehicle for more than a short while. Remember: Professional car thieves do not take more than a few minutes break open and drive away a car. Automobile Security devices (s21)could deter the potential thieves from attempting to steal your automobile.
While leaving the car ensure that all windows, doors and the boot are properly locked up. Windows must be rolled up to the maximum as any gap over there can be exploited to open the door lock with the help of a wire.
The radio antennae should be telescoped in or pressed down along the body of the car at night. Otherwise there is a good chance of finding it vandalized in the morning.