A radar object detection system includes a radar sensor and a controller. The radar sensor is configured to emit a radar signal toward a defined area proximate to the vehicle, and output a reflection signal indicative of a detected target present in the defined area. The controller is configured to receive the reflection signal from the radar sensor, determine if the detected target corresponds to a trailer towed by the vehicle, and define an exclusion zone characterized as occupied by the trailer and thereby excluded from the defined area where objects can be detected.