DETROIT — General Motors plans a new family of rear-wheel-drive vehicles for Pontiac. The G8 line will include a sedan followed by a wagon and sport truck.

All will be modeled after products sold by GM's Australian subsidiary, Holden, according to three sources familiar with the project. The vehicles will be assembled in Australia.

The G8 sedan goes on sale early next year. It replaces the Grand Prix and will be Pontiac's flagship sedan with a starting price around $25,000.

The G8 wagon will be a performance vehicle similar to the Audi A3 wagon, sources say. The G8 sport truck will be reminiscent of the Chevrolet El Camino, which was produced in North America from 1959 through 1987.

The vehicles will closely resemble the Holden VE Ute sport truck and Commodore wagon.

There was debate within GM about whether to give the sport truck to GMC. GMC won't get it.

Instead, GM's marketers wanted — and will get — a Pontiac sport truck so GM can market the three rwd vehicles as a high-performance family.

The sport truck will have the same drivetrain as the Chevrolet Camaro, and it will use a modified sedan architecture.

The 2008 Pontiac G8 sedan is the first U.S. vehicle developed on GM's global rwd sedan architecture. The Camaro will be the second. The G8 sedan will be assembled in Australia and will share much of its sheet metal with the Commodore.

There is one caveat: Sources say the wagon and sport truck may be repriced or canceled if the U.S. dollar continues to drop. The Australian dollar is currently worth 90 cents in U.S. currency, up from 79 cents in August.