I found this post from Classical Drive to be pretty informative:

Speculation in the auto industry, especially in Europe, is of a vehicle type called the shooting brake, which some pundits suggest is the next little big thing. Here in North America you'd be hard put to find anyone who knows what shooting brake means, so permit me educate you. It was originally conceived as a sporting vehicle with room for firearms and dogs that gentlemen could drive to the hunt; in Britain a station wagon is often referred to as an "estate" or "brake," so add "shooting" and you get the picture. There's nothing new about this; as long as I can remember, custom builders have converted Aston Martins (see photo) and Jaguar E-Types and even Ferraris. Volvo made a delectable production version, the 1800ES, from its P1800 coupe. Chevrolet's Corvette-based Nomad concept has driven enthusiasts crazy for fifty years, to the point where GM recently previewed a modern concept while still refusing to make a production version. Truth is, the market for such a car is small, but with modern niche marketing the shooting brake could find sufficient buyers to justify the expense. Would you buy one? Would you tell your friends it's a shooting brake? Please add your comments using the box below.

Found at: Classical Drive