[KarlInOhio]

A Prius is 183 inches long and 69 inches wide. It looks like the panels have about 75% coverage, so that's about 6 square meters. That's a maximum of 6 kilowatts. At 25% efficiency that's 1.5kW maximum of charging or driving power. Wikipedia lists a Tesla 3 as using 26 kWh/100 miles. Assuming the Prius is similar, you would have enough charge after an hour in noon sun at the equater to drive a little more than 5 miles.

[mrsmith]

5 miles might get you to a gas station.
Where you could call a tow truck to take you to a charging station.

[RegulatorCountry]

Or, for a retiree or person working from home you could potentially have a hundred miles or more of range to work with if the car is parked outside in a given sunny week, and still maybe half that in overcast. I can see that being very appealing under certain circumstances if the car is not too awfully expensive. Buying one off lease that’s a few years old might be a good deal if the battery and solar don’t degrade much in that time. I’ve heard of first generation Priuses being used as taxis abroad going many hundreds of thousands of miles without the battery pack going bad. Something to consider, could be a great thing for a second vehicle or primary if you do mostly local driving. Have to keep the roof clean and clear though, not a vehicle for someone who seldom washes their car.