The G6 is sold as a 2 door coupe, 4 door sedan, and 2 door convertible. The convertible has been sold since 2006.
The G6 name comes from another famed Pontiac nameplate, the Grand Am. It is the sixth generation of the Grand Am line, although the Grand Am was retired several years ago. Either way, the changes made for the G6 are significant, and it was a big hit from almost the moment it hit dealer lots. It is now the 11th top selling car in the United States, and it's looking to climb that ladder even more in the coming years. It also has received several awards from the top car review magazines.
The base engine on the G6 is a I4, but there are several V6 engine options.
Besides the base trim, the G6 is sold as a GT and GTP. Each offers better performs than the base model thanks to better tuning and higher compression ratios on the engine.
The G6 had one of the biggest launches of any cars in history. Pontiac achieved this by giving away 276 G6's to people in the audience at a taping of the Oprah Winfrey Show. The cost of 276 cars was far outweighed by the estimated $110 million in positive publicity the car received as a result.
The G6 is just starting to hit the used car market, mostly with off-lease vehicles. If you would like to buy a used Pontiac G6, I suggest looking at eBay before you go anywhere else, just to see where the prices are for different years and mileage. Buying off eBay is also a lot easier than you might think, and many of the car sellers are also professional car dealers who will be able to help out with things like shipping.