Painting side mirror

I recently bought a new side mirror for one side which looks really good, but my other one looks real old. If I were to paint it what kind of paint should I get to make it shiny like my new one which looks as if it has a clear coat and where can I get it? Also do I need to sand it before painting and if so with what grit sand paper?

http://www.automotiveforums.com/vbulletin/showthread.php?t=391672

Id assume that would work the same on the mirrors as well