Detroit LIVE: Buick Avista sport coupe concept

The concept reportedly shares proportions with the Camaro.

This is the Buick Avista sport coupe concept, in all its sheet-metal glory.

It was already expected that Buick would be debuting the China-built Envision crossover at the big Motor City shindig, but GM's entry-premium brand had an additional surprise in the works.

Ahead of the North American International Auto Show, Buick has revealed a sports coupe concept reported by Bloomberg to be about the size of a Chevrolet Camaro with 2+2 seating. Buick says it is holds 400 horsepower under the hood, generated by a turbocharged V6. That engine configuration builds upon the mills that power the LaCrosse and was likely chosen as an homage to the Buick Grand National of the 1980s, which has a cult following among enthusiasts.

There is no word on whether the concept previews a production model, but if it does, it seems quite likely that it would share its bones with its muscle car cousin. General Motors could easily reskin the Camaro to create a Buick version. The concept is an effort to lower the average age of Buick buyers and shed the brand's image of being a retiree's car. The current age of a Buick customer is 59. That means it's hot on the heels of Lexus at 57 and a marked improvement over the 60-something average from 10 years ago.

With its "That's a Buick?" ad campaign, first-ever Superbowl ad, and a new product onslaught in the coming years — including the Avenir Concept-based LaCrosse and a convertible Cascada — the once-staid brand is hoping get its 223,000 in annual US sales closer to the 1 million it moved in China last year.

Live Images by Brian Williams.