Abstract: A method and device for attaching directly to a high-profile and/or elongated item of cargo (10, 110) transported on the exterior payload area of a vehicle (16) prevents collisions with obstructions (36, 136). A detector (38, 138) remotely detects a distant obstruction (36, 136) in the path of the cargo (10, 110) using ultrasonic, infra red, or other sensing techniques. The detector (38, 138) is mounted directly to the cargo (10, 110) by a mounting member (42, 142) which releasably surrounds at least a portion of the cargo (10, 110) and provides an enveloping, frictionally constricting engagement so as to maintain the detector (38, 138) in a preferred operating orientation. The mounting member (42, 142) preferably includes a bracket (44, 144) configured to attach at multiple, spaced points on the cargo (10, 110).