Buick's higher-tune Sportback has been spotted in the wild.

The enthusiast-oriented variant of Buick's Regal Sportback was spotted testing in Michigan, giving us a hint at what will likely be the final U.S. design for the sportier five-door.

The Chinese version of the hopped-up Regal was leaked back in April, and from what we can tell, not much will be different. Despite the extensive camouflage wrapping, we can see this car shares the leaked Chinese model's aggressive front bumper and fog light designs and its integrated exhaust finishers.

There's also an obvious difference: This mule has a different wheel design featuring exaggerated split spokes, reminding us a bit of the design of the outgoing model's wheel, where the Chinese model's is a bit more reminiscent of some of Volkswagen's wheel designs.

Another difference lurks beneath the hood, thanks to information gleaned from another leak earlier this year. A blurb mentioning the Buick Regal GS Sportback model was spotted on the company's web site and quickly removed. That tidbit revealed that the North American model will likely be powered by GM's 3.6L V6 rather than another turbocharged four-cylinder.

We expect front- and all-wheel-drive models to be available, but don't hold out hope for a manual transmission on either.

Photos by Brian Williams.