The driver’s loss of attention is an important problem in which are spent considerable research efforts in different areas such as psychology, automobile technology, computer vision and driving assistance. We use here a simple algorithm based on rigid-body and motion detection. This scheme efficiently segments moving objects using the visual field of the driver’s rear-view mirror. The overtaking scene in the rear-view mirror is distorted due to perspective, making it difficult to detect the overtaking car. Thus we propose two alternative methods to deal with this problem and compare the results in different overtaking sequences.