Summarize:

Of the three sticky substances that can dry on your car - bugs, sap and tar - tar is the easiest to remove. Not only that, but there are a variety of household substances you can use to loosen the tar. Smother the tar in one of the following substances for 1 minute to loosen the tar: WD-40 (not for use on windshields and windows) Goo gone Peanut butter Commercial tar remover Use a soft cloth to wipe off the loosened tar. If it holds fast, apply more product and wait a few minutes before trying again. Continue smothering tar in the product you're using and wiping it off until the car is tar-free. After the tar is gone, wash your car to get rid of residue from the tar-removal product.
Smother the tar with a product to loosen it. Wipe away the tar. Wash the car.