https://www.cnet.com/roadshow/news/audis-next-panoramic-roof-could-pack-solar-power/ >Audi announced Wednesday that it teamed up with Hanergy, a Chinese solar cell specialist, to develop a thin-film solar array embedded in a panoramic glass roof. Audi believes the entire roof can be covered in cells that could provide additional benefits to vehicles. >You'll probably need more than one cell to cover the roof.