Chrome Tail Pipe Black Spot Remover
In the past with any chrome or stainless steel tailpipes that I have on my vehicles there would appear black spots, like tar splatters, that would require lots of rubbing with chrome polish/wadding for removal only to reappear frequently.
A guy at work with asphalt tack coat splashed on the side of his car used a product called "Tarminator" to remove it. Bought a spray can of it from an Auto Zone or Advanced Auto store and sprayed it on the chrome exhaust tips. It is a simple spray and rinse with water that is supposedly harmless to clear coat and the like. With little or no rubbing the black spots came off. Even the unpolished segment of the exhaust looked like new. The product is designed to remove pine sap, etc from painted surfaces.
Beats the heck out of spending an hour or so rubbing with chrome polish.