With its prototype series of Astro concept cars, GM showed drivers a possible vision of a future that never fully arrived.

GM has crafted some radically cool concept cars that should have made it to production, but unfortunately fell short.

Now, the car is crossing the auction block ... Just take a glance at this Buick Blackhawk concept with a shape right out of the '40s or '50s. Despite the heritage styling, it was pieced together ...

The concept car was born in the US back in 1938 when Buick introduced the Harley J. Earl-designed Y-Job. In the following decades, these show cars (or dream cars, as they were often called ...