The only way I find it to get it off is if I use a special bug spray for the car just as it happens. But the tree sap that is dry won't come off!!!!!!!
I need to get it off because sooner or later I'll have to replace my windshield. I can barely see past it.
The tree sap is all over my windshield, bumper, hood, side panels.
Kerosene, or gas. RainX helps a little on the windshield, as does a good quality wax to protect the paint. Use a WORN OUT kitchen pot scrubbing pad (like the Scotch Bites), as they will abrade the sap without removing the paint. It's much more soluble when it's warm or hot. Some people use a little Kerosene in water to clean thier windshields, and I'd venture a guess that this practice would help stop the sap from sticking to it, in the first place.