From this article I thought the car was going to be based off of the same car the GTO is based on.
I think they have the same number of doors, same drive train... different retro cool styling.
"The car is 186.2 inches long and rides on a 110.5-inch wheelbase. The wheels are 21s at the front and 22s at the rear, shod with monster 275/30 front and 305/30 rear tires, which should be able to corral the 400 horses from the LS2 6.0-liter V-8 engine powering through a six-speed manual transmission. The show car has a cobbled together chassis with an all-independent suspension, but if it makes it into production, it will use the so-called Zeta Lite architecture that will be shared with Holden in Australia. The good news for GM is that the architecture--while hardly cutting edge--is far more sophisticated than the live-axle Mustang. Insiders say that a $20,000 base model production car could use an inexpensive V-8 (the LS2 would come in a costlier model), so a V-6 version would be offered only to make the car easier to insure. The real car would have smaller wheels, but the overall diameter of the tires wouldn't be much changed. GM vice-chairman and product czar Bob Lutz apparently loves it and joked on the show stand "all I have to do is persuade this man"--referring to GM CEO Rick Wagoner--"to pay for it."