Any body have any idea what this solar panel is mounted on the front license plate area? There is a wire that runs to the positive terminal in the fuse box.
I'll also vote for a kludged 12V trickle charger. Does it have a glass front plate cracked by rock damage? If so, it is probably toast, having lost whatever weak charging ability (due to poor location and sun angle) it may have had. If so, and unless it has a blocking diode, the reverse leakage at night and in poor light probably exceeds the daytime gain. So I suggest that you disconnect or remove it.
Such an odd place\angle for a solar panel...unless.....if u parked the car at a certain angle as the sun was coming up or going down..... nah, nevermind. lol. Ya, not really the best place for a trickle charger...
If there had been two wires there it may of been for a connector to a maintenance charger, some people fit them for when they are away from the car for a while. The charger stays in garage and its output plugged in to a connector often behind the number plate.
A vertical solar panel will have near zero efficiency. Whatever it is, more likely it is 12V powered; something like a red light camera or radar jammer...
