Here is one of the concept designs.  This design has both riders sitting side by side.  A jackshaft will be used to combine the rider power to the single rear wheel drive.  The overal length with fairing is around 12 feet.  Weight is much less than the HPV from the 2006 competition.  Aerodynamics is what the vehicle lacks because of the frontal area.  Surprisinly, the frontal area of the side by side model pictured here is less than the frontal area of the 2006 competition vehicle, which was an in line design.