Yea, Nu-finish is a brand. I found they have car wash, scratch doctor, polish, and vinyl cleaner. Don't see anything for metal.
http://www.nufinish.com/products.htmlCan find this stuff at KMart, Napa, Auto Zone, WalMart, tons of places...
I was thinking something like Mother's Back-To-Black, but I looked it up and it says for rubber, plastic, and vinyl too. No idea what it would do on metal, but I'd try it.