Abstract: A plurality of spaced tracks are affixed to the roof of a vehicle and extend from side to side of the vehicle in parallel relation with each other. A platform having approximately the same dimensions as the roof of the vehicle has rollers affixed to an underside thereof rollably mounting the platform on the tracks for movement to a position covering the roof and to an extended position extending beyond the roof from a side of the roof in approximately the plane of the roof. Support posts support two corners of the platform farthest from the vehicle when the platform is in its extended position for maintaining the platform at approximately the level of the roof above the ground whereby the platform in its extended position covers an area of ground alongside the vehicle.