How expensive would it be to build a car that is powered strictly by solar energy?

and also by the energy generated by its wheels turning while moving. Of course I understand that it would have to be able to store the solar and kinectic energy to be used later on demand..

I know this is possible, but I would like to know how much you think it would cost, and the reason for that is to find out how far away we might be from having a production car like this.