1. A method for controlling an object-presence alert in a vehicular side-object detection system in response to a remote sensor for sensing objects in a predetermined zone of interest along side a vehicle, said zone of interest including a front region and a rear region, said remote sensor providing sensor data to generate a set of localized detection points, said method comprising the steps of: when detection points are sensed in said zone of interest, then collecting a plurality of respective sets of detection points at successive sample times; for each of said sets of detection points, determining a tracking type of said object within said zone of interest in comparison to a speed of said vehicle and classifying said object as either a moving vehicle or a stationary object in response to said tracking type and in response to locations of said detection points in said zone of interest; if said object first appeared in other than said front region, then selecting a short observation period including a first predetermined number of sets of detection points and otherwise selecting a long detection period including a second predetermined number of sets of detection points longer than said first predetermined number; and comparing a number of times that said object is classified as a moving vehicle within said selected observation period to a predetermined percentage threshold and initiating said alert if classified as a moving vehicle for greater than said predetermined percentage threshold.