This method has worked for me, MOST of the time, clean the area with a mild soap & water wash, use a spray type detailing liquid, wash again, then use a clay bar (available at auto parts stores) to go over the area, wash again if stain persists, try using a bug/tree sap remover (auto parts store again) re-do the clay bar routine, if satisfied use a sealant protectant afterwards ( I use a product called Rolite Premium Polish & Sealant ( used on ELITE aircraft ) best of luck .... Boo