90 % isopropyl alcohol works well. Daubing it rather than rubbing it seems to work best. It dissolves the sap but leaves a little residue that washes off easily.
I was near Concord NH last September for 5 weeks and had to get a lot of pine sap off my patio awning, window awnings, roof and car so I am speaking from experience.
Clay WA5NMR - Ex Snowbird - 1 year, Ex Full timer for 11 years - 2004 Winnebago Sightseer 35N Workhorse chassis. Honda Accord toad.