DETROIT – Clearly taking aim at the successful Miata and Mini, General Motors Corp. debuts here at the 2004 North American International Auto Show its ’06 Pontiac Solstice and the Chevy Nomad and Saturn Curve concept cars.

The vehicles all are based on GM’s new rear-wheel-drive small car platform called Kappa. Bucking a tendency that has dogged its recent history, GM is joining a trend as it’s emerging – the return of mainstream, reasonably priced RWD cars – rather than after it’s already peaked.

The Kappa architecture features full-length hydroformed frame rails and a stamped steel structural tunnel, which houses the transmission and the driveshaft. GM claims Kappa isn’t a version of its front-wheel-drive Delta small car platform – Ward's previously reported that the auto maker was working on a knock-off called “Delta with a tunnel.”

“We knew we needed a small flexible RWD architecture,” says Lori Queen, vehicle line executive-GM small cars.

“The closest we had was Delta. We talked about tunneling it. But we knew that wouldn’t cut it. We needed a new architecture.”

Solstice will go on sale this fall.

First shown as a concept at the 2002 North American International Auto Show, the Solstice roadster immediately gained a huge following. Production plans for Solstice, due in dealerships this fall, have been the worst-kept secret in Detroit with details slowly filtering out over the last two years and GM executives openly talking about efforts to make the car.

Neither volume nor pricing has been announced, but GM developed the Kappa platform in order to have small RWD cars to sell for roughly $20,000.

“True to the thinking behind the original concept, the production Solstice is all about being a ‘back-to-basics’ roadster with gorgeous lines and fun-to-drive characteristics,” says Bob Lutz, GM vice chairman-product development and chairman-GM North America.

GM stayed faithful to the 2002 concept car’s proportions and the design. In fact, it may be GM’s best concept-to-production execution in recent memory. “Put them side by side and it’s very difficult to tell the production model from the concept,” says Franz Von Holzhausen, Solstice design manager.

Solstice only will be offered as a convertible. There are no plans for a coupe. Solstice’s reverse clam-shell hood hides a 2.4L variable-valve version of GM’s Ecotec all-aluminum DOHC 4-cyl. engine, producing about 170 hp. At the start of production, Solstice will be offered with an Aisin 5-speed manual transmission.

The nose features Pontiac’s dual-port grille. The car’s stance is wide with 5-spoke wheels at the corners. The front end is bulbous and hangs low. A sheet-metal crease runs over the high-arching front wheel wells. The rear is tightly stacked with aerodynamic curves behind the two headrests. It’s definitely a Miata fighter with Euro-styling.

Solstice’s wheelbase is 95.1 ins. (241.5 cm). It sits on monotube shock absorbers and coil springs, 18-in. wheels, 4-wheel disc brakes and independent front and rear suspensions that feature forged aluminum upper and lower control arms.

GM hasn’t confirmed Solstice’s production location but it likely will be Wilmington, DE, or Ramos Arizpe, Mexico.

While Solstice is bound for dealerships, GM will gauge auto show reaction to the Nomad and Curve before deciding if the cars should be built alongside Solstice.

This is the third Nomad concept.

GM thinks Nomad, which shares its name with two previous GM concepts, could compete against BMW’s Mini. The auto maker even takes a shot at Mini in the Nomad’s press kit, calling it the “miniscule chap from across the pond.”

Notably, the 2-door Nomad wagon also has a European styling flavor. GM’s U.K. studio helped design the Nomad, and well-known Italian coachbuilder Pininfarina SpA helped assemble the vehicle.

“The Nomad is the type of vehicle that creates an instant bond with certain personalities,” says Simon Cox, design director, GM Advanced Design, U.K.

Draped in an icy blue color, Nomad features a sharply raked B-pillar and a fish mouth-shaped grille. The rear is busy with vertical lines on the folding tailgate, elongated tail lamps, a removable roof panel and dual exhaust. Under Nomad’s hood is a turbocharged Ecotec 2.0L 4-cyl. 210-hp engine. It is paired with a new 5-speed automatic transmission that features finger-operated tap shifting.

Nomad boasts independent front and rear suspensions. To make room for rear-seat passengers in its 2+2 configuration, the Nomad rides on a 107-in. (271.8) wheelbase.

The interior features a fan-shaped central gauge cluster mounted in the dashboard, black leather trim, blue aluminum gauges and techno blue lighting. The rear seat offers functionality; the center armrest folds to store long items while each rear seatback folds to increase the Nomad’s overall cargo space.

The Curve concept inevitably will be compared to the Chrysler Crossfire.

Curve easily is the most gorgeous and aggressive Saturn – concept or production vehicle – in the brand’s history. Exterior styling features a mix of the Chrysler Crossfire, Alfa Romeo and the Saab 9X concept from 2001. However, if GM decides to build Curve it likely would sell for less than anything offered by those brands.

Like Nomad, the Curve was designed in Europe (by GM stylists in Sweden) with final assembly assistance from Pininfarina. GM’s North American design studios also contributed.

The vehicle is soaked with a liquid metal silver hue. A front-hinged, clamshell hood is complemented by a rear-hinged trunk lid. The powertrain consists of a supercharged 2.2L Ecotec 4-cyl. engine that produces more than 200 hp and a Getrag 5-speed manual gearbox. Seven-spoke, outboard-style 20-in. wheels are mounted to performance tires and fitted to Curve’s chassis. Fourteen-inch brake rotors, with twin-piston front calipers and single-piston rear calipers, provide the vehicle’s stopping power. Curve’s wheelbase is 107-ins. (271.8 mm)

The interior features an open-gate shifter, analog instruments, a curved wood center console, charcoal-colored leather and aluminum door handles.