World Solar Challenge 2015 Movie: worlds first family solar-powered car I think it would be really fun to modify a Tesla Model S or Roadster 3.0 and enter the race. I would cover the car with solar panels and put on narrow low rolling resistance tires and call it done. You get to charge once per day, and need to cover 3000km in less than 40 hours of driving over 5 days to win. That's only about 375 miles per day and an average speed of 45mph. You get penalized for using energy from the grid, but you could make up for the speed advantage you would have over the pure solar cars.