General Motors Kappa platform

In 2002, the Pontiac Solstice Concept was shown in two forms: a drivable roadster convertible, and a design study of a fastback coupe.

The drivable roadster concept car shown had been cobbled together from many different components, using a heavily modified portion of the Delta and Epsilon.

It is speculated that when General Motors decided to try to produce the Solstice as a highly styled, low-cost, low-volume niche vehicle for enthusiasts, it became apparent that there were no existing platforms that could be used to achieve the needs of a modern compact rear wheel drive roadster.

It features hydro-formed rails and a tunnel structure derived from the Corvette architecture and Sigma, and is designed for a short-long-arm suspension for the front and rear.

[2] Three other concept vehicles were built on the initial Kappa platform, and shown at the 2004 NAIAS: The Vauxhall VX Lightning, The Saturn Curve and Chevrolet Nomad.

The Saturn Curve and the Chevrolet Nomad concept cars were built on "modified" versions of the Kappa platform, and exhibited 12 inches longer wheelbases, and 2+2 seating.