It seems an odd time to unveil an upscale convertible. So are Saab’s designers incurable optimists, or did they just fail to notice that summer’s over and a global financial meltdown has started?

Well, maybe not. With its 47 mpg hybrid powertrain and clean looks, maybe this “vision of the future of open-top motoring” really does have a future. Something very like this probably will be the next generation in Saab’s 25-year history of four-seater cabrios.

The 9-X Air’s curvy nose is familiar from the previously-seen 9-X BioHybrid concept, so it’s most visually striking feature is the innovative treatment of the rear window area. In a conventional open-top car, there are no metal pillars behind the rear doors, and the rear window is stitched into the fabric top (or integrated with the folding metal top for a coupe-cabriolet). But in the 9-X Air, the car’s trunk sides swoop up, almost fin-like, to meet the fabric “Canopy Top” at roof height, with the rear screen remaining permanently fixed in place between them. When you open the roof, it really is just the roof.

The rear profile appears rather heavy and coupe-like in photographs, but much lighter and more elegant in life. There are many advantages to this design, including a larger rear screen (for better visibility), improved strength, a reduction in wind buffet, a smaller surface area of fabric which takes less stowage space, and better efficiency,

aided by a clever auto-adjusting wind deflector fitted to the windshield that ensures a smooth airflow over the car.

The efficiency story continues under the hood, where there’s a GM hybrid powertrain (Saab is a subsidiary of GM.) At 1.4 liters, the gasoline engine is small (or “rightsized” in Saab-speak). Burning  E-85, whose superior burning characteristics allowed a higher compression ratio and higher pressure turbo, it offers a claimed 200 horsepower, 207 lb-ft of torque, 47 mpg, and (important in Paris) impressive 107 g/km CO2 emissions. Performance is a respectable 0-62mph in 8.1 seconds, though when run on gasoline, all-round performance is reduced.

All of which sounds quite tempting, especially the news that the $4 gallon hasn’t sounded the death knell for optimists or open-top motoring.