There is a wide array of warning systems, back up cameras, and video displays designed to eliminate the blind spot behind cars and trucks.

Ultrasonic Systems
Ultrasonic proximity sensors act like rear-view radar and are relatively inexpensive. Some models require that holes be drilled in car bumpers to install two or more sensors; others can be installed easily inside trailer hitches. Prices start at $180, plus installation. Sites: Audiovox, www.audiovox.com; Echomaster, www.echomaster.com; Sense Technologies, www.sensetech.com

Video Systems
A growing number of options are now available from several manufacturers. Most include a camera, cables, and a small LCD screen that can be mounted on a dash or visor. Prices start at $140 but typically cost several hundred dollars, plus installation. Sites: Audiovox, www.audiovox.com; Hitchcam, www.hitchcam.com; HMI International, www.hmiinternational; Roadmaster, www.roadmasterusa.com; Mito Corp., www.mitocorp.com

Factory Options
If your vehicle already has a built-in navigation system, all you may need to add is a video camera. However, because of the complexity of many of today’s computer-based navigation systems, installers and manufacturers often suggest you go to the dealership if you want the rear-view image to appear on the existing nav screen. Cadillac, Chevrolet, Honda, Lexus, and others offer a dealer-installed rear-view camera option for several models. J-Q.com