Oh these arent panels... its just paint that will be able to provide some energy back into the system... it is just an idea to help out with economy.
most likely they will only be able to run the radio or some smaller accessory while the car is running... or it can be recharging the caps when it is parked outside.
The specs of the paint show that it is good at converting light even at low intensity and off angles into usable energy... I think thats why it is so intriguing. These could be efficient even on a cloudy day.
here is an article about it from a quick google search.. im sure there are other sites where you can look up this information.