I just got a brand new bike with a matte black finish - I'm curious myself what others suggest specifically for a bicycle with matte black. At least for cleaning. My Harley has a matte black finish and they recommend Windex without ammonia for cleaning. I've been doing it for over 5 years and it works great! Still as matte black as ever. I've got some Bike Nashbar bike polish for my old bike that I've used on it, but I question if it will harm the finish now that the question has been raised.