Seems not pessimistic enough to me. Realistically most people would capture on average, while the sun is up, about 100 watts if they covered their car in solar

Seems not pessimistic enough to me. Realistically most people would capture on average, while the sun is up, about 100 watts if they covered their car in solar panels. A car needs at least 10 KW to cruise at 60 mph. This means you need to charge for 100 hours for 1 hour of driving. Actually 200 hours because you can't charge at night-time.