[Snax]

Solar car roofs don't make sense in any practical terms unless you have to deal with being away from the grid. It makes for more sense to place panels on a fixed roof optimized for solar exposure, vs. the sometimes and likely far less than ideal exposure of a car roof.

More simply, if you have the grid and can wait for car solar panels to charge the car, you can wait for the car to charge plugged in - from panels working far more efficiently.