Abstract: An instrument for cleaning the undercarriage of a motor vehicle includes an elongated, tubular support member that is adapted to receive an input supply of a particular fluid, such as water. The support member is connected in fluid communication with a generally rectangular cleaning head that is shaped to define a plurality of outputs through which the fluid is dispensed. The plurality of fluid outputs are arranged in first and second linear arrays, the second linear array of fluid outputs being disposed in a parallel and offset relationship relative to the first linear array of fluid outputs. A plurality of wheels are preferably connected to both the support member and the cleaning head. In this manner, the instrument can be easily rolled underneath the undercarriage of a vehicle.