And it'll only take about 350,000 miles of driving to recoup the investment...
and that's assuming gas was selling for $3 a gallon. Only, it isn't. Gas is less than $2 a gallon at many stations here. That'd push the payoff to something like 550,000 miles. It's cool from the geek factor but makes no sense at all from an economic point of view. Plus, it takes 746 watts to produce 1 horsepower (at 100% efficiency). Those solar panels put out 30 watts. That suggests the 10% improvement they're claiming is "questionable."