So, my proposition is this: (Note that this is a purely theoretical project, and no models/experiments are necessary.) When a car moves forward, wind moves backward, right (relatively). So if we were to attach a small, retractable wind turbine to the side, connect it to the alternator, we could potentially power the headlights/alternator stuff-essentially taking load off the engine. Ordinarily, the rotation of the wheel powers the alternator (which consumes petrol). So, instead, if we connect a wind turbine to the alternator, we use less petrol (I've calculated approx how much by using calorific value, energy reqd. for battery charging, energy reqd. for head lights etc.) I've also calculated turbine size/capacity that is required to save a decent amount of petrol. Is this a valid theory? Is it too simplistic for an 11th grader? What are the points I need to include in my project report? Do I need essential additions that I left out?