The subsequent installation of Cinderella Travel in an existing motorhome can cost a lot of time and money, as in many cases major adjustments are required inside the vehicle. For this purpose, the prefabricated installation unit has been developed, offering a practical alternative to installing the toilet's installation components in walls and adjacent cabinets. With the built-in unit, less or no expensive custom work is required. The unit mounts to the existing wall and conceals the vent pipe and toilet installation components.