When it comes to automobiles, no one snubs conventionality like the French. Citroën is the classic case in point. The company's postwar everyman's car, the 2CV, was like no other. Its DS series, which arrived in the 1950s, was uniquely futuristic. So when Citroën set out to build a range-topping grand touring coupe, why wouldn't it have been any different? Or, more accurately, why shouldn't it have been wildly different?

The Citroën SM arrived with the dawn of the 1970s, making its debut at the 1970 Geneva auto show. Building on the themes of the DS, it featured hydro-pneumatic suspension, steering, and brakes, and a smooth, radically tapered body design (the front track is nearly eight inches wider than the rear) that was shaped by aerodynamics. The (six) covered headlights included inner high beams that could swivel up to 75 degrees. The V-6 engine came via Maserati, which Citroën had recently purchased, and the "SM" stands for System Maserati. Fed by a trio of two-barrel Weber carburetors, the aluminum-block, DOHC unit was mounted backward behind the front axle, its transmission pointing toward the front (drive) wheels. Four-disc brakes provided stopping power, and the fronts were mounted inboard to reduce unsprung weight. Top speed was an advertised 140 mph.

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The SM wasMotor Trend's Car of the Year for 1972, beating out the Porsche 911S and the BMW Bavaria. For Eric Holveg's Swiss-born stepfather, the SM was a dream car, but it was a dream that remained out of reach. Instead, the family owned a series of DS Citroëns. "I guess that's why I never learned how to be afraid of French cars," says Holveg, who has owned this SM since 1990.

"French and Italian—it sounds like a nightmare marriage," he acknowledges. "But it's actually quite reliable." Holveg has put more than 50,000 miles on this very clean example, which now has 87,000 miles on the clock. He's also driven this SM cross-country. "It's a great all-day driving car," he says. Our drive was considerably shorter, a daylong meander through the Hudson River Valley.

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One look at the ultra-mod interior, and we couldn't wait to try out the lounge-like seats. Indeed, the full leather seats—which Citroën bragged were "contour-molded"—are as comfortable as they look. The SM's unconventional styling extends to the interior, with oval gauges and a single-spoke oval steering wheel. The heavy chrome pieces exude quality, not surprising in what was an unabashed luxury car. Standard equipment included air-conditioning (working, in Holveg's example), power windows, and an AM/FM stereo—the latter mounted sideways on the console under the passenger's left elbow. The wraparound windshield and large glass area afford a great view for the driver and three passengers.

There's nothing ordinary about the way the SM drives. You start the engine and first feel the rear of the car rising, then the front. (Next to the driver's seat there's a lever to adjust the ride height.) The 90-degree V-6 is a little lumpy at idle, but get the revs up and the Maserati engine growls toward its redline. It also pulls strongly—Citroën put the SM's 0-to-60-mph time at 8.2 seconds. The linkage for the five-speed gearbox is a joy. The big, chrome gearshift needs just a nudge in the right direction and it clicks right into gear. (A Borg-Warner three-speed automatic was also offered.) The steering is relaxed on-center but very quick once you begin to turn—it's only two turns lock-to-lock, and the self-centering is pronounced. The oddest aspect of the driving experience, however, is the pressure-actuated brake, which is a mushroom-like button on the floor rather than a pedal.

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The Citroën's most charming characteristic is its incredible ride quality, as the car glides over road imperfections. Yet you can throw it into a corner and the body leans up to a point, then just hangs on. The SM may look like an otherworldly device but, really, it's a high-performance grand touring coupe, a car that was designed to whisk rich Parisians to the CÔte d'Azur with speed, comfort, and style.

"People are beginning to realize what a special car it was," says Dave Burnham, of Dave Burnham Citroën, a longtime marque specialist located near Albany, New York. "There weren't too many other cars that could do what this car could." And there are absolutely none that did it the way Citroën did.

The Citroën's most charming characteristic is its incredible ride quality, as the car glides over road imperfections.

Why buy?

You march to the beat of a different drummer—especially if that drummer plays "La Marseillaise." Of course, one need not be a Francophile to appreciate the SM, but it probably helps. The SM is a highly unconventional exotic, but it's also a very comfortable, drivable GT that feels younger than its 40 years. The SM was a head-turner when new and is even more so today. Prices appear to be on the move, and some of the very best examples—usually prepared by SM World, in California—have crossed the $100,000 mark.