DETROIT | Pontiac wants to add variants of the eagerly awaited G8 rear-wheel -- drive sport sedan to broaden the model's appeal.

A station wagon and sport-truck variation are among the possibilities for the Australian-built car that is to go on sale next spring.

"It's very likely we're going to get more variants" of the G8, a General Motors Corp. source said, speaking on condition of anonymity because the automaker is still considering which G8 models to offer. The sleek sedan will become the flagship for Pontiac's return to its performance heritage when it replaces the Grand Prix sedan in 2008.

GM's Holden Australian unit builds the wagon and pickup models as part of its best-selling Commodore VE family of vehicles. The G8 is a mildly revised version of the Commodore VE sedan. Its sporty looks are reminiscent of a BMW 5-series, and it is the first production model from GM's global Zeta family of rear-wheel drive cars, which also will produce the Chevrolet Camaro and a number of other models GM's North American plants will build for several of the automaker's brands.

"It's optimistic to think that all the body styles Holden builds could come here," the source said.

The weak U.S. dollar makes importing the wagon and pickup a dicey proposition, and GM isn't sure how much demand there would be for either of the cars. GM has not said how many G8s it expects to sell annually, but it is likely that even the sedan will be a low-volume model unless GM decides to build it in North America, which is unlikely to happen before 2010 or 2011.

Pontiac will offer 261-horsepower V6 and 362-horsepower V8 versions of the G8, priced at $26,910 and $29,310, respectively. The brand also is considering a high-performance GXP.