Many have modified their Priuses, and one of those possible modifications is a rooftop solar panel system. It seems that Toyota is considering the same as standard equipment for its own models, but only for high-end models, and only to power the AC.
Toyota Motor Corp plans to install
solar panels on some Prius hybrids in its next remodelling,
responding to growing demand for "green" cars amid record-high
oil prices, a source briefed on the matter said on Monday.
The panels, supplied by Kyocera Corp would be able to power
part of the air-conditioning on high-end versions of the
gasoline-electric Prius, the source said.
"It's more of a symbolic gesture," said the source, who asked
not to be identified. "It's very difficult to power much more
than that with solar energy."
Yes, but you could use the panels to power, or rather, charge the hybrid's batteries, which is what some after-market vendors have done. One such vendor, for example, is SEV (their roof panel is shown above).