A radar object detection system configured to detect objects proximate to a vehicle, said system comprising; a radar sensor 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; a controller 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, wherein: the detected target corresponds to the trailer if a range to the detected target varies less than a variation threshold for greater than a time threshold, and if the range is less than a maximum distance threshold, a length of the exclusion zone is determined based on a longitudinal distance to a most-distant target that corresponds to the trailer and is closer than a maximum trailer length, a width of the exclusion zone is determined based on a lateral distance between a left-most target that corresponds to the trailer and a right-most target that corresponds to the trailer, and the controller is configured to determine if the detected target corresponds to the trailer only when a present speed of the vehicle is greater than a speed threshold. a radar sensor 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; a controller 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, wherein: the detected target corresponds to the trailer if a range to the detected target varies less than a variation threshold for greater than a time threshold, and if the range is less than a maximum distance threshold, a length of the exclusion zone is determined based on a longitudinal distance to a most-distant target that corresponds to the trailer and is closer than a maximum trailer length, a width of the exclusion zone is determined based on a lateral distance between a left-most target that corresponds to the trailer and a right-most target that corresponds to the trailer, and the controller is configured to determine if the detected target corresponds to the trailer only when a present speed of the vehicle is greater than a speed threshold. the detected target corresponds to the trailer if a range to the detected target varies less than a variation threshold for greater than a time threshold, and if the range is less than a maximum distance threshold, a length of the exclusion zone is determined based on a longitudinal distance to a most-distant target that corresponds to the trailer and is closer than a maximum trailer length, a width of the exclusion zone is determined based on a lateral distance between a left-most target that corresponds to the trailer and a right-most target that corresponds to the trailer, and the controller is configured to determine if the detected target corresponds to the trailer only when a present speed of the vehicle is greater than a speed threshold.