The making of a coupe.
The new coupe was inspired by the Solstice coupe concept shown at the North American International Auto Show in 2002. True to the concept, it is a modern sports car with classic lines. The roofline has a “fastback” shape with stylized “rails” that run from the front of the roof to the rear, culminating in a stylish and functional ducktail-style rear spoiler.

The coupe’s roof is fixed aft of the B-pillars, with side windows and a rear liftglass for access to the cargo area. The roof panel is easily removed from the passenger compartment, and an optional soft roof cover stores in the cargo area. A home storage case for the roof panel will be offered through GM Accessories.

Engineering the design.
Despite its dramatic new look, engineers made only minor structural changes to create the Solstice coupe. The rear fenders and rear fascia are the same as those on the convertible. New taillight assemblies flow more smoothly into the tapered roofline.

“The Solstice coupe represents a major collaboration of design and engineering,” said Bruce k*o*sbab, chief engineer. “The sleek lines of the new roof give the car a fresh appearance, yet only minimal changes were made to the body structure – it’s a great example of building on an already solid foundation.”

Lightweight structure.
The roof’s structure was strengthened with additional support elements, including an aluminum roof bow attached with aluminum brackets. The bow and brackets are stiff, yet low in mass, a design feature that pervades the coupe’s overall construction. The roof includes a lightweight sheet molding compound cover affixed to a rigid aluminum frame for additional lightweight support. A lightweight magnesium roof panel frame weighs just 31 pounds (14.2 kg) and can be removed by one person. The cover is also made of sheet molding compound.

Powertrain and suspension.
Because the change to a coupe body style resulted in only a slight increase in curb weight, no drivetrain or suspension changes were necessary to shift from the convertible body structure. Initial tests have shown that the Solstice coupe will deliver ride and handling, acceleration, braking and fuel economy comparable to the convertible model.

The coupe is powered by a standard 2.4L Ecotec four-cylinder engine that generates 173 horsepower (129 kW), while the GXP version is equipped with a 2.0L turbocharged Ecotec engine with 260 horsepower (194 kW).