My XJ got covered in tree sap last fall (on the hood, roof, side, rear window, and plastic bumper caps.) I tried Dawn, Goo Gone, and at least one tar/sap/grease remover. Nothing worked.
Then I used 90% Isopropyl alcohol. It melted the sap and it wiped right off!!
94 YJ, 2.5L, 5sp Sold.
97 TJ, 4.0, 5sp Sold.
01 XJ, 4.0, Auto