The buggy is a high-speed off-road vehicle that was originally used for recreation on Rook Island by its more wealthy residents, then was later used for recreation on top of the bodies of those residents. These lightweight cars are ideal vehicles for rapidly navigating the roughest sections of the island.
As the in-game description mentions, this is one of the ideal vehicles when you're heading off road, and they are actually one of the better vehicles in the game.
