HOLDEN has come clean on its worst-kept secret: GM Daewoo's S3X concept will morph into a production four-wheel drive wagon as part of its line-up in 2006.

To prove it, at this morning's Sydney motor show opening Holden pulled the covers off a Lion-badged version of the S3X, which will eventually take over from the homegrown – but slow-selling – Adventra crossover as The General’s rival for Ford’s successful Territory and Toyota’s Kluger.

Codenamed C-100 and first revealed as the Chevrolet S3X concept at the 2004 Paris motor show 12 months ago, the South Korean-manufactured seven-seater 4WD is now undergoing final prototype testing in Seoul prior to the start of production late this year.

While the production S3X, expected to hit the market in the first half of next year, finally gives Holden a fully fledged member in the booming SUV market segment, the mid-sizer will be followed by a smaller version based on the Daewoo’s C-105-codenamed T2X compact 4WD show car revealed at this year’s Seoul motor show in April.

It is believed S3X will be available with both five and seven seats, as well as – like Territory – the option of all-wheel drive or two-wheel drive (in this case front-wheel drive).

Eventually giving Holden a full range of off-road models will be a South African-built, right-hand drive version of the Hummer H3, which is not scheduled to appear here until 2007.

Holden says its production version will closely resemble the S3X showcar revealed in Sydney, the look of which was influenced by former Holden design director Mike Simcoe, who was head of GM Asia-Pacific Design when the car was developed, and Max Wolff, who is now deputy director of advanced design at GM Daewoo Auto & Technology.

Describing S3X as the company’s "most purposeful step into the SUV arena", Holden chairman and managing director Denny Mooney today said: "The S3X production version will fill Holden’s most obvious portfolio gap in a truly convincing way.

"It will deliver three rows of seating to accommodate seven in comfort and will provide sporty suspension allowing the type of driveability which people expect from Holden," he said.

Sydney’s S3X features heavily flared wheel arches wrapped around 20-inch nine-spoke alloy wheels, metal bumper inserts, horizontal wing vents, a panoramicc sunroof, jewel-like headlights and a separately-opening rear window. At least the final two elements should grace the production version.

According to Holden, S3X’s wheelbase of about 2700mm makes it comparable with Kluger, while its 4639mm length is closest to BMW’s X5.

Other vital statistics include a width of 1848mm and height of 1722mm, which also make S3X similar in dimensions to Territory, of which Holden makes no mention.

Inside, there is a combination of wood and metal highlights, while an onboard infotainment system includes a DVD-based navigation system linked to a 180mm monitor.

Though the S3X concept is powered by petrol-electric hybrid technology – which Holden says offers "a glimpse into GM’s potential future propulsion systems” – the production vehicle will be powered by a 3.2-litre version of the Holden Alloytec V6 engine made in Port Melbourne.

European models will use a 2.8-litre version of the Alloytec, as well as new Korean-built turbo-diesel engines, which may eventually be offered here as well.

Holden also used this year’s Sydney show to debut its new Daewoo-sourced Barina light hatch replacement – which Mr Mooney confirmed will be joined by a sedan version based on the Aveo concept - the new Viva small car and the Efijy hotrod showcar – see separate reports.