GM Service Manual Online
For 1990-2009 cars only
    â€¢ The following materials may damage the vehicle finishes if left on painted surfaces:
      â€¢ Calcium chloride and other salts
      â€¢ Ice melting agents
      â€¢ Road oil and tar
      â€¢ Tree sap
      â€¢ Bird droppings
      â€¢ Chemicals from industrial chimneys
    â€¢ Use cleaners that are designated safe for painted surfaces for the removal of these materials.