Blk Mirror housings keep turning grey

[AUDIJIM at aol.com]

You might think this sounds crazy and I'll go on the record that I never  
tried it, but a friend of mine said to use old diesel motor oil on black trim  
that was sun faded. He said it nearly stains the black plastic black again. I  
have a spare set of sun faded mirror housings, but I do not have access to any  
diesel motor oil (used) except what's currently in my truck. And it's not due 
 for an oil change any time soon.
 
Jim