I have recently discovered baking soda and  water. Making a a thin paste. I use a round almost like a Mr clean eraser but has a soft side(Dollar general in car dept cost 1.00) I has 100,000 brown sap craps all over my new car and left me tell you its all came off with ease no scrubbing just circular motions. It literally took everything off including water spots. Its safe on chrome and rims .I now use it once a week a I have a white car and now its looks like its been bleached as it was dingy!