Way to go Spain. It is time that the rest of the world follow Spain's example. Especially big cities around the world. I don't understand why electric cars do not have solar panels as their roofs. Majority of cars are parked outside in the sun all day anyway. Why not charge up the battery using the sun's energy even if it is for only a small amount. If all electric cars have them, it adds up and perhaps not build too many generating plants to keep up with the demand.
Cost? Price will come down as soon as we can mass produce them.