When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
This was suggested to me, I tried it and it worked (on my black Grand Prix no less)
Use an orbital buffer and apply liquid bug and tar remover to the terrycloth pad. Work it in and the spots go away. Use a liquid bug and tar remover (not a paste) such as "turtle wax" makes.
I was hesitant to do this at first, but it did work for me.