Say I use my car for the daily commute and I'm some 10 miles away from office. I work 8 hours in the office in daytime, and leave my car in the parking. For when I'm going back home, my battery would be topped up.

I'd need to recharge my car much less, once a month maybe.

Also, say you can do 300 miles with a full charge. Depending on how fast you go, you'll do those 300 miles in 5 to 10 hours. So on average, a the solar aid would give you some additional 15 to 30 miles, ie 5%-10%. Which sounds nice to me.

All with the current technology. Obviously there are tradeoffs, in R&D, price and weight.

But it seems like worth pursing, log-term.