A method and system of avoiding a collision between an object attached to a rear of a vehicle and an object behind the vehicle during reverse maneuvering of the vehicle includes determining with an electronic control unit of the vehicle an adjusted top height of a first object attached to a rear of the vehicle. The electronic control unit then determines whether the adjusted top height is lower than a clearance height of a second object behind the vehicle and unattached to the vehicle. Upon determining that the adjusted top height of the first object is not lower than the clearance height of the second object, the electronic control unit determines that the first object would collide with the second object if the vehicle is reverse maneuvered too close to the second object and upon determining that the collision would occur alerting a user of the vehicle.