The House-Wagon bears a slight resemblance to a British AEC Routemaster double-decker bus, even though it is yellow. The interior is a lot smaller than an average house. The main entrance is the kitchen, the bathroom is small, and the second floor is one bedroom.
Oolong uses it in Diablo Desert for him, Goku and Bulma to stay the night in. The next morning, Yamcha knocks it over using his Panzer Faust, forcing the Dragon Ball Gang to leave it behind. It blows up after they left, when the bomb Shu planted on it that morning goes off.
The House-Wagon also appears in the film Dragon Ball: The Path to Power, where it plays a more prominent role and becomes the groups main way of transportation through a majority of the film.
Video game appearances
In Dragon Ball Z: Budokai Tenkaichi 3, the House-Wagon appears in the Desert stage (like most vehicles in the game it is destructible).