General Motors was the first manufacturer press conference of the 2008 North American International Auto Show and it made a big splash with no fewer than six 2010 models as well as three concept vehicles – one of which will be in showrooms in 2011.

If two is company and three’s a crowd, what are 600?

Although GM cut back on much of the glitz usually contained in its displays for the Detroit Auto Show, it more than made up for this shortcoming by showing up at this year’s press conference with 600 company employees, more than a dozen current, future and concept vehicles as well as various company and government dignitaries that included GM Chairman Rick Wagoner, Vice Chairman Robert Lutz and Michigan Governor Jennifer Granholm.

So it was in front of this group as well as about 5,000 journalists from around the world that GM introduced its two latest concept vehicles as well as one that was first introduced in Paris last year.

Cadillac Converj Concept

Cadillac Converj

Without a doubt the most stunning concept at this year’s NAIAS (we’re not alone in thinking this, it received one of only two EyesOn Design concept awards given out at this year’s show), the Cadillac Converj is not just a sexy coupe. Underneath its glamorous exterior, the Converj is an extended-range electric vehicle (EREV) that shares the same Voltec technology as its more Plebian counterpart, the Chevrolet Volt.

Cadillac Converj Concept

Although equipped with a gasoline engine as well as an electric motor, the fossil-fuel engine merely acts as a generator to recharge the vehicle’s batteries as the electric motor always furnishes the primary propulsion. In the words of the immortal bard Justin Timberlake, the Converj brings “Sexy Back” to Cadillac.

Chevrolet Spark

Chevrolet Spark

Inspired by the popular Beat concept vehicle that has toured auto shows for the past couple of years, the Spark concept is said to be a much closer to the look of the actual production vehicle that will be sold in global markets (read: Europe and Asia) in 2010 and planned for the U.S. in 2011.

Chevrolet Spark

While the style and color are certainly more imaginative than anything currently offered by Chevrolet in North America, the size and marketing demographics are almost exactly the same as those of the current Chevy Aveo. No word yet on whether the Spark will be sold alongside the Aveo or if it will replace it.

Chevrolet Orlando

Chevrolet Orlando

Although introduced at the Paris Motor Show in October of last year, the Orlando made its North American debut in Detroit. Originally intended as an overseas model, last summer’s spike in fuel prices convinced GM that they needed this kind of a vehicle in the U.S.

Chevrolet Orlando

Based on the same global platform as the upcoming Chevy Cruz, the 7-seat Orlando seats passengers in three rows of theater-style seating. In Europe, the Orlando is powered by a 2.0 liter common rail diesel engine that produces 150 hp and 236 lb.-ft. of torque. According to GM, the Orlando will go on-sale over here in 2011.

Cadillac Converj