It only "keeps going" for 44 miles:
"In optimal conditions, the solar panels can add up to 44 miles a day to the 388-mile range the car gets between charges"
While definitely an interesting implementation of a long discussed concept, it's practical use is very limited.
At the stated price point ($250K),
So the ~ $200K over a Model 3 price point, would buy me upto 44 miles / day of free electricity.
44 miles / day ~= 12.54 kW (given my historic 285 Wh/mi).
At $0.14/kWh, that's $1.7556 / day (under optimal conditions).
Assuming you drive every day, that's $640.79 / year.
The break-even for the extra $200K for the solar panels is ... therefore ... ~312 years.
Hard pass.
My break-even for solar panels in NJ was ~22 years.
That made it a hard pass as well.
But I'm glad the technology is progressing in the right direction.