Aptera is attempting to do this. They had to engineer their own solar panels for the car. Probably the closest thing they have to production ready. They also had to make the car super efficient to make it work. Peak output of their design is about 700W
If you figure 10 hours of that (or longer but with less-perfect conditions) you can get 7kWh. I estimate about 3.5 miles per kWH on my Bolt. Not sure this car's efficiency, but it gives us a ballpark number. That would give about 25 miles of driving. I understand that there are plenty of other factors that can go into this, but "fewer than 10 miles in perfect conditions" isn't necessarily accurate either.
I would respectfully argue that 5 hours of peak output equivalent is more realistic as that's what you'd get from static panels at the proper angle. But I didn't figure in the claimed efficiency of the car.
My car, Ford cmax energi, was tested with a 500 watt panel and that only yielded 5 miles a day in great conditions. More like 2-3 miles most days, and that's at roughly 300wh/mi., similar to your bolt. Never made it to production with solar.
But even that number you say is realistic, about half of what I just said, would still give a little more than the "less than 10 miles under perfect conditions" - I still don't think it's really that practical or worth the cost for a number of reasons, but I also like crunching numbers to know what it would look like before making that judgment.
Curious, how did you get power from a solar panel into a high-voltage battery?
Wasn't me personally. Solar was tested by the university of Georgia iirc. And I'd assume some sort of DC boost converter to boost the 30v to 300v when connecting the panel to the battery pack