Greg,
Is there a good / easy / painless way to remove large amounts of tar from painted surfaces?
If you use something to scrape some of the tar off that won't scratch the car if you slip(like maybe a plastic knife), WD40, or any other solvent, such as diesel, turpentine, paint thinner(mineral spirits) should take the rest of the tar off.
I have a citrus based product that works good too, but it's an industrial product and not readily available to the general public. It's called "Misty Solvent Cleaner and Degreaser" and the can states that it is made by AMREP, Inc., 990 Industrial Park Dr., Marietta, GA. It is pretty awesome. I buy it at an industrial cleaning supply distributor.
Standard solvents should do the trick, though.
Have fun, Phil |