SW meaning in Governmental ?

A station wagon (US, also wagon) or estate car (UK, also estate), is an automotive body-style variant of a sedan/saloon with its roof extended rearward over a shared passenger/cargo volume with access at the back via a third or fifth door (the liftgate or tailgate), instead of a trunk/boot lid. The body style transforms a standard three-box design into a two-box design — to include an A, B, and C-pillar, as well as a D-pillar. Station wagons can flexibly reconfigure their interior volume via fold-down rear seats to prioritize either passenger or cargo volume.

The American Heritage Dictionary defines a station wagon as "an automobile with one or more rows of folding or removable seats behind the driver and no luggage compartment but an area behind the seats into which suitcases, parcels, etc., can be loaded through a tailgate."

When a model range includes multiple body styles, such as sedan, hatchback, and station wagon, the models typically share their platform, drivetrain and bodywork forward of the A-pillar. In 1969, Popular Mechanics said, "Station wagon-style ... follows that of the production sedan of which it is the counterpart. Most are on the same wheelbase, offer the same transmission and engine options, and the same comfort and convenience options."

Station wagons have evolved from their early use as specialized vehicles to carry people and luggage to and from a train station, especially to estates, and have been marketed worldwide.