What if there was a way to use the same film that covers most vehicles (Windows) which protect us from the suns rays. Use that film to charge up the battery pack. It would I guess have to be really thin and could backup the braking and gas motor which recharges the battery pack. Just think the film could be used mostly during daylight driving and then for night time driving that's where the brakes and gas motor kick in. I guess there would have to be a switch to go from film to the gas motor and brakes.
If the film wasn't enough then the brakes could be included to help recharge the battery pack. If enough power could come out of the film maybe the hybrid could travel futher without the use of the gas engine.
Most cars I've seen have all the windows covered except the front and front side windows.


P.S. I wasn't suggesting that the film would power the hybrid alone during daylight driving, it would reinforce the braking or gas motor.