Panels are installed in locations and at angles to avoid shading as much as possible, but when you have the panel on your car, you have none of that luxury Tha

Panels are installed in locations and at angles to avoid shading as much as possible, but when you have the panel on your car, you have none of that luxury That sounds like a shortcoming of implementation, not proof that the concept is bad. Yes, I'm suggesting that cars with solar panels should have tilting, sun-tracking roofs. Not that it matters. The reason cars do or do not come from the factory with solar roofs is sales. If the market pays for it, it stays. If they don't, then it goes. I've seen countless people pay thousands of dollars for "ground effects" which are nothing but painted plastic glued and/or screwed to the car body, chrome packages, blackout packages, and 'leather' seats that are actually vinyl and less comfortable than cloth. A significant portion of the automotive market is driven by aesthetics, misinformation (e.g. 'leather' seats), and consumer fantasy. How many dudes driving huge diesel trucks do you see actually towing heavy loads or picking up shipments at a loading dock? This is just the green version of the same fantasy marketing. Incidentally, I would love a solar roof if only to power a fan to keep air circulating when I have to park in the sun, and to trickle-charge the battery when I'm away on vacation. Not everything has to be an ideal solution to powering transportation.