Introduced in 1982, the Buick Regal Grand National began life as a special edition honoring Buick’s back-to-back titles in NASCAR’s Grand National series. Cars built for the 1982 model year were sprayed in Charcoal Gray with unique body graphics, and the standard engine was a somewhat anemic 4.1-liter V6, rated at just 125 horsepower.

No Grand Nationals were built in 1983, but in 1984 the car returned with an all-new, take-no-prisoners focus. Black was now the chosen color, and power came from a turbocharged 3.8-liter V-6, good for 200 horsepower and a seriously impressive 300 pound-feet of torque. The legend of the “misfit Buick” in black had begun.

By the end of production in 1987, Buick’s most powerful Grand National, the GNX, was putting out a conservatively rated 276 horsepower and 360 pound-feet of torque according to Wikipedia. That made the boxy, understated Regal one of the quickest cars you could buy at the time, at any price.

As Autoblog explains, a new documentary called Black Air covers the history of the 1984 - 1987 Grand Nationals, which remain as much of an oddity today as they were back in the day. They certainly didn’t fit into the staid and leisurely image of GM’s lower luxury brand, and no Buick since has offered comparable levels of performance (although the current Buick Regal GS is a step in the right direction).

Black Air will be released on December 11, but attendees of the Buick Performance Group meeting in Hebron, Ohio, will be able to catch an excerpt from the film on August 4. In the mean time, enjoy the film’s trailer, which will likely raise more questions about the Buick Regal Grand National than it answers.