I have been building solar electric vehicles for years. In 2009 I built a 72 volt EZ-GO golf cart and in 2012 another golf cart and a 1973 Harbilt English postal van. These vehicles were real workhorses. Just park them in the sun! But something was missing. I realized I needed to take it to the highway. I chose a Volkswagen Bus for this reason and also the surface area of its roof. I imagined a large PV (photovoltaic) array that could tilt for maximum solar exposure. It also occurred to me that the large space underneath the panels could offer some more elbow room in the vehicle.