That's a great technology... I thought it would be great if they did that and you just answered that thought...
I just bought a 13 W suitcase style solar charger... forgot the controller...will be here by Friday. It's supposed to be great for solar charging devices like laptops cellphones etc and keep a car battery topped off and charge up etc... It's just over 1 Amp, so nothing major, but I want to see how it will perform for keeping my car charged up. I plan on taking the alt belt off and testing on my drives to and from work... only about 6 miles, so I am pretty sure this thing will easily keep with that usage. My MPGuino can keep me alerted to the battery voltage
If for some reason this has trouble keeping up, I'll just up to a 50W or 100W panel.