What: The BlockerBeam, a unique safety feature debuted in the 2000 Ford Excursion:

Why: In 2000, showing the foresight that would lead to the collapse of the American automotive industry, the Ford Motor Company produced a vehicle that can only be described as obscene. The Excursion was an SUV big enough to haul nine Big Mac-loving Americans, a number which exceeded its city MPG. Before it hit a single road, the Sierra Club awarded this monstrosity a special “Exxon Valdez Award.” It was so tall, it didn’t fit in most garages. And this meant it posed a risk never seen on a consumer vehicle. In a collision with a smaller car, the car could pass directly under the Excursion—the bottom half, anyway. The top half would be sheared clean off, decapitating the more energy-efficient driver and her passengers. Ford didn’t like the thought of leading the world in decapitations, so it developed the BlockerBeam, a hollow sub-bumper extending six inches below the frame. Its purpose was to catch the the colliding vehicle’s bumper, stopping it in its tracks. The shock would then ripple through the bumper and up through the vehicle (yours, not the Excursion, which will hardly notice). So if you hit an Excursion, you will still suffer massive plastic and elastic deformation, but you will not be decapitated. In all likelihood, you’ll leave a good-looking corpse.

Impact: Well, that’s what it’s all about, isn’t it. The BlockerBeam saves the lives of drivers who don’t feel the need to bestride the earth like a colossus. The Insurance Institute for Highway Safety lauded Ford for installing the beam itself rather having been ordered to do so, which is refreshing. It’s now standard equipment on slightly more sensible vehicles like the Lincoln Navigator and the Range Rover. The Excursion is no more, a victim of its own irrelevance.

Personal Connection: What’re you, mental? I hate big cars. My post-Chevette car was a baby blue Metro ragtop, which could turn around in a parking space. Thereafter, Evon had to politely demand that our next car have a back seat. Thus, I’m much more likely to appreciate the BlockerBeam from the exterior of the Excursion rather than the interior, in the same way I’d appreciate an angry Mike Tyson wearing boxing gloves.

Other Contenders: the ’59 Caddy’s tailfins; the spine on the 1937 Bugatti T57 SC Atlantic, possibly the model for the dorsal fin on the 1940s Batmobile; a refrigerated glove box, such as the 2008 Dodge Caliber SRT-4’s Chill Zone; Jatech’s disappearing car door (watch the door close in motion); all of the standard equipment on James Bond’s Aston Martin DB5; the JATO—I know, but I want it to work.