FRANKFURT — General Motors Corp. uses the eve of the Frankfurt auto show to unveil a luxury sedan concept from an all-new global premium large-car platform.

The auto maker aims to re-enter that market with products for several continents, including North America.

The first look at the premium platform is the captivating Opel Insignia concept, a 4-door “personal car” embodying a more muscular and upscale look for Opel going forward.

“For a product of this size, to get the best economics, you need to — and you can — sell it in several continents,” says Rick Wagoner, GM chairman and CEO, adding that a production model is “several years away.”

Look for heavy involvement by GM subsidiary Holden Ltd., says Wagoner, noting the Australian auto maker stuck with the segment when others abandoned it.

Holden's VE Commodore was not a viable starting point, however, as it is well into its lifecycle. Wagoner says GM wanted to start with a new rear-drive platform. The expectation is cars from the new platform will be built in Australia as part of the global platform rollout.

And Wagoner says past experience has shown a good platform tends to spread to a broader range than initially intended. Nor does it have to be just a premium platform, he tells Ward's.

The Insignia provides a dramatic look to a segment dominated by more conservative shapes, such as the BMW 5-Series. The Opel concept has a bold grille, accented by small, high-set 3-dimensional headlamps, wide stance, long wheelbase, short overhangs and a “V” crease down the middle, similar to the Chrysler Crossfire.

At first glance, the Insignia looks like a coupe, with wide front doors.

The absence of a B-pillar or rear-door handles is explained with the push of a button that sends the rear doors sliding backward, parallel to the body, like a minivan, while the front seats move forward for better access.

Another of the 45 electric adjusting motors retracts the center console into the trunk, and a foldable fifth seat falls into place. The massive transmission tunnel also slides open to reveal a DVD player, cooler for two bottles of champagne and a humidor.

The rear hatch opens as a unit — or the window can open alone. The drivable concept borrows the 344-hp V-8 from the Chevrolet Corvette.

The interior gets away from heavy reliance on the metal look that GM Vice Chairman Bob Lutz says he is tiring of, and sliding covers conceal systems such as air conditioning and infotainment.

Don't assume the Opel Insignia will be the first production vehicle, Wagoner tells Ward's. It just made for a great concept, showcasing a number of innovative features and a rich, tobacco-brown leather interior.

And while he hints Buick would be a good candidate, Wagoner declines to say whether it might be the frontrunner for the new platform.

No approvals have been given, but more than one product is under consideration. Wagoner also declines to say whether other candidates exist in prototype form.

Meanwhile, Opel has a vacancy in its slot for an upper midsize luxury sedan, with a V-8, says Opel Chairman Carl-Peter Forster. The rear-drive Insignia fills the gap nicely, while representing Opel's vision of the future.

That vision also is evident in the third-generation Opel Astra, also unveiled at the Frankfurt show (see p.23).

GM unwrapped the Opel Vectra Caravan, an elegant and versatile sedan with a flexible interior like that of the Opel Signum. Wagoner describes it as an important building block in the renaissance of a more upmarket Opel.

The No.1 auto maker used the press preview to show the Daewoo Lacetti (which Wagoner pronounces La-shetti in Europe after debate with those who call it La-Setti). In Asia, the 5-door hatch is known as the Nubira, and it will be sold as the Suzuki Forenza in the U.S.

Adding to the Saab lineup at Frankfurt was a 9-3 sport hatch concept, a 5-door cross between a hatchback and a wagon.

The Cadillac SRX made its European debut, rounding out a European lineup that includes the CTS sedan and XLR roadster.

The onslaught is in keeping with four key elements to the overall GM plan, says Wagoner: strong product even when markets are weak; aggressively fighting for every sale; continuous improvement to quality and cost; and generating cash for future products and growth.

Wagoner says GM unabashedly is on a mission to design and build the best products in every market of the world.