Quadricycle is a four-wheeled vehicle.  The most common layout is when the wheels are placed at the angles of a rectangle.  The alternative layout is when wheels are placed at the angles of a rhombus (or, more generally, at the angles of a geometric kite).

The rhombus layout is not very convenient, because such vehicles are less stable and also they leave 3 tracks instead of 2.  Still there have been some experiments.