I don't know if it's sap, some bird with mega turds or some sort of glue grease from a vandal, but it's on my hood and my front window. It's not a lot, but I am using soap and it's just not coming off. If I put a lot of soap on and then use my fingernail, it does come off, but it is really persistent. How do I get this off my car without ruining the paint? I used alcohol on the glass as I know it's safe there.