Method of operating a vehicle surrounding area monitoring system and surrounding area monitoring system

The method involves a signal generator (32,34,36,38) generating a warning signal if an object, especially another vehicle (26), is within the non-visible region for the driver (18) when looking in a rear view mirror (12,14,16). A warning signal can also be generated if an object is in a region bounding on the non-visible region. The non-visible areas are fixed, pre-settable values. Independent claims are also included for the following: (a) a computer program for implementing the inventive method (b) and a control and/or regulation device for operating a vehicle environment monitoring system (c) and a vehicle environment monitoring system.