A method for testing a vehicular driving assist system includes positioning the vehicle near a target object such that the target object is within a field of sensing of at least one sensor of the vehicle. The vehicle has an ECU having electronic circuitry and associated software, with the electronic circuitry of the ECU including a processor for processing data captured by the at least one sensor to detect presence of objects in the field of sensing of the at least one sensor. The vehicle is maneuvered away from the target object and, as the vehicle maneuvers away from the target object, the data captured by the at least one sensor is recorded. The recorded data is reversed to indicate the vehicle is approaching the target object. The reversed recorded data is provided as an input to the vehicular driving assist system to test the vehicular driving assist system.