Going Nowhere: 8 Automotive Technology Dead-EndsIllustration by Natalie FossHere's a good way to know if you're doing things right as an innovator: see if other people copy your work. Generally speaking, trailblazers making a good path wind up with a whole conga line behind them. Those pursuing ideas that don't have widespread appeal, however, will often find themselves alone in the wilderness, and all too often wind up turning back, leaving that attempted course to be lost to history.The following eight examples showcase automotive tech that, for whatever reason, never quite caught on with the mainstream. Even if some of them are awfully cool.1) Gesture ControlPhoto credit: Illustration by Natalie FossBMW debuted this weird tech in 2015. Thanks to a sensor, you could control infotainment functions with hand movements without touching a button. Few liked it, and it lasted until 2025. It's better to use a knob than to look like one.2) Audi UFO BrakesPhoto credit: Illustration by Natalie FossIn a standard disc brake, the caliper sits on the outside of the disc. Unfortunately for Audi's V8 executive sedan, the car's 15-inch wheels didn't allow for discs large enough to deal with the curb weight. Audi's doomed solution? Mount the brake caliper on the inside of the rotor with a surround that looks a bit like a flying saucer. They were complex and expensive to replace. They died in the U.S. with the V8 sedan in 1994.3) Talking CarsPhoto credit: Illustration by Natalie FossBack when Nissan was trying to shift away from its Datsun branding in the U.S., someone had the idea that a properly high-tech luxury car should talk to you. The Voice Warning system, which could issue alerts about an open door or an engaged parking brake, used tiny phonograph records at first. These days we make do with old-fashioned beeps and chimes.4) Turbine CarPhoto credit: Illustration by Natalie FossThe jet age brought an insatiable desire on the part of automotive engineers to put turbines into cars. Everyone from Fiat to Ford made prototypes, but perhaps the best-remembered effort was the Chrysler Turbine. Fifty vehicles were lent out for use on public roads, and they actually worked, idling at 18,000 rpm at start-up. Most were scrapped when the program ended;just nine survive.5) Rotary EnginesPhoto credit: Illustration by Natalie FossSpinning triangles have engineer-pleasing character, but they make the accountants sad. Rotary engines have been part of Mazda's DNA for so long that it's the only automaker that refuses to give up on the concept. The others learned long ago that the rotary's fuel consumption, emissions production, and peaky performance weren't worth chasing with R&D dollars.6) Bose Active SuspensionPhoto credit: Illustration by Natalie FossDeveloped at a reported cost of over $100 million under the code name Project Sound, Bose's active suspension leaned on the company's expertise in high-fidelity audio. Conventional springs and dampers were replaced with electromagnetic actuators, turning a test-bed Lexus LS400 into a machine with less roll than a BMW M5 but better ride quality than a Citroën DS. The car could even jump over obstacles. Regrettably, the weight and cost of the suspension kept it out of production.7) Michelin TRXPhoto credit: Illustration by Natalie FossBy pairing wheel and tire as a package, Michelin's TRX system gave cars wearing the early low-profile radials a more compliant ride. In the Eighties, the setup was good enough to be offered on the Ferrari 308, the Renault R5 Turbo, and even the Ford Mustang. But tire technology advances quickly. Conventional tires caught up to the TRX and did not require specific wheels.8) Disappearing DoorsPhoto credit: Illustration by Natalie FossCar doors have opened from the front, from the back, from the top, and even on an angle, as in a modern McLaren. Back in the mid-Eighties, BMW's engineers had the idea that doors could just disappear entirely. In the Z1 roadster, built from 1989 to '91, you open the door with the press of a button that rolls down the window and retracts the door entirely into the sill.If You Can Only Own One Car, Make It One of TheseThese Are the Most Popular Cars by State