Pound your brother real good! It won't help your sap problem but it will make you feel better. Cool1 is right, get in and remove any trace of the sap, even if you use wax and grease remover plus put silicone drops in the paint it wouldn't garantee a smooth and well bonded coating...and you don't want to paint the car only to rub the car back again because the sap kept on messing with the finish. Sounds shitty but painting is all about prepping...gotta get that right.