How do you  remove paint from the exterior of your car?
 You can use finger nail polish remover on a cotton ball. After the sap is removed, make a paste of water and baking soda to wash the affected area, then apply wax. 
Another method to remove the sap is to use mineral sprits. Use a soft, terry towel, or wash cloth dampened with mineral sprits. After removal, wash the car and apply wax to the affected area. Tree sap can also be removed by using a water-soluble paint brush cleaner. 