We still don’t know the name of Buick’s all-new small sedan that will take its place right under the 2011 Regal in the carmaker’s line up, but these latest spy shots from Germany give us our best look to date of the upcoming compact-sized model’s exterior and interior design.

And if the styling looks familiar that’s because Buick’s baby sedan is in essence the North American version of the upcoming Opel Astra sedan.

From what we gather by looking at these revealing spy shots, the only differences worth mentioning aside from the badges concern Buick’s signature waterfall grille and possibly, the styling of the tail lights.

As with the 2011 Buick Regal and the Opel Insignia, the small sedan’s interior is identical to that of the recently revealed Astra hatchback.

There are no surprises under the sheetmetal as Buick’s Opel-sourced model uses the same Delta II platform found on the Chevy Cruze.

Even though it’s too early to know specific details about the powertrain options, we reckon that Buick’s compact sedan will probably be offered with a similar engine range to the Cruze including a 1.4-liter turbocharged four-pot, and quite possibly, the Astra’s more powerful 1.6-liter turbo with 180 ponies.

The big questions, is how U.S. consumers will receive Buick’s smallest proposal that will compete head on with the VW Jetta and its like, especially after the failure of Saturn’s version of the Astra.

Of course, the are many significant differences between Buick’s and Saturn’s Astra, the most important being that the Buick is based on the new and not the previous generation Astra, it will come with more powerful and modern engines and that it’s a four-door sedan and not a five-door hatchback.