A hybrid car with solar... duh!

Car manufacturers should add a few solar panels on the top of hybrid cards. Not just for when cars are running, but to take advantage of all the time that they spend sitting out in the sun. My Honda Civic Hybrid has relatively small battery capacity because it is optimized for accelleration/regenerative breaking, so perhaps a larger battery capacity would be required to utilize the extra charging.
This doesn't seem too expensive or technically infeasible. It could at least make up for the energy lost to air conditioning in sunny areas.
If and when we switch to Hydrogen cars, why not have our cars use solar electricity to electrolyze more H2 while they are sitting?! Wouldn't it be nice to return to our cars after work and see that they have filled themselves up!? Same goes for compressed air cars.