Motown's top models

(Fortune Magazine) -- The dirty little secret of the North American International Auto Show in Detroit is that the car manufacturers closely gauge media and crowd reactions to the concepts they unveil. The more we (you) like it, the likelier they are to build it - or push it forward as a priority.

This year, while attendees swooned over Shades of Green (hybrid, electric, and fuel-cell powertrains), they also fell for Topless Decadence, exemplified by the $400,000 V-12 Rolls-Royce Phantom Drophead Coupe. With a hand-buffed brushed-steel hood accenting its snooty snout and a teak deck adorning its considerable posterior, it was the most sumptuous car at the show. Which other fantasies should become reality? Here are my picks.

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The next blockbuster cars Car companies are coming up with a lot of radical ideas. Here are ten that should go the distance, from Detroit's 2007 North American International Auto Show. (See the cars)

Most promising hardware: GM's Chevy Volt, an electric vehicle that will recharge on a normal 110-volt outlet and have a range of 40 miles on battery power and a 640-mile maximum when the one-liter gasoline backup engine kicks in.

Vice chairman and red-blooded sports car lover Bob Lutz was the force behind the striking (and Camaro-resembling) Volt, which he says wasn't an easy sell in the boardroom. "I have never been more excited about a car in my entire career," he told me.

The Volt is built on GM's new E-Flex platform, which uses electricity to drive the wheels and can accommodate gas, ethanol, biodiesel, or hydrogen propulsion systems. I hope GM (Charts) stays focused on such long-range - and costly - technology; the world is watching. (See the Chevy Volt.)

Most promising software: Ford Sync. Developed with Microsoft (Charts), Sync is a voice-activated system that will allow occupants to verbally control phone calls, text messages, and iPods. If it does what it promises, Sync will be a real tech and safety boon. (See the Sync system.)

Most disappointing announcement: Ford (Charts) will put Sync only in 12 Ford/Lincoln/Mercury vehicles for at least the first year. No wonder Ford's European brands struggle to get ahead - Volvo, Land Rover, and Jaguar owners are paying a premium and not getting the cutting-edge technology of... a new Focus. Go figure.

Most likely to succeed: Toyota (Charts) FT-HS sports car concept. Edgy design, Prius-based hybrid system, sound performance. The awkwardly named coupe proves (as if George Clooney hasn't already) that green can be quite sexy. (See the FT-HS)

Most audacious: Audi's six-liter V-12 TDI Q7. With the diesel engine that won Le Mans last year, this SUV boasts 500 hp and 737 foot-pounds of torque at 1,750 to 3,000 rpm. Take that, Porsche Cayenne Turbo! (See the TDI Q7.)

Most fun: Ford Airstream Concept, a plug-in hybrid hydrogen fuel cell that operates full-time on electric power. It's retro-futuristic (think 2001) and functionally delightful, with a 360-degree videoscreen, swiveling pod chairs and a Thermos-shiny exterior. (See the Airstream -- and the team that designed it.)

Most sophisticated design: Jaguar C-XF. Jaguar's design chief, Ian Callum, unveiled the first 100%-Callum car. Some see it as too great a departure from "Jaguarness." Others, like me (full disclosure: I worked at Jaguar years ago), see a muscular yet curvaceous shape that is every bit a Jag. The pressure is on: It must boost sales for the struggling marque when it goes on sale next year. (See the C-XF.)

Most attractive crossover: Jeep Trailhawk. Ruggedly handsome, it's an attitude-filled four-seater built to be smooth on the road - and capable of off-roading lite. (See the Trailhawk.)

Most intriguing concept: Mazda Ryuga (Japanese for "gracious flow"). The undulating car, with double gullwing doors, signals a radically new direction--one that may help convince the world Mazda is serious about speed and performance.

See Sue's picks from Detroit.