Haven't purchased the PV panels yet. It is a definite, though.
Voltage was at 12.05 today when I got home. I think it was fully charged when I left, but I'm not sure. I had to make both trips with headlights on since I stayed late at work.
I have a 175 mile trip Sunday-Tuesday; I will test on the way home how far I can go without dropping below 12V on a straight road trip.