I did a high-level study a while ago. It makes no sense for cars, or boats, to consider solar panels. They just don't produce enough energy to justify their presence there.
It might make sense if you incorporate solar panels into large sails, but the engineering required to make it work (main problem: too much weight; not enough elasticity) is essentially unsolved for now.
It might make sense if you incorporate solar panels into large sails, but the engineering required to make it work (main problem: too much weight; not enough elasticity) is essentially unsolved for now.