rejuvinating "greying" black plastic

This is not really a question but an answer to people who may wish to blacken there old plastic parts on there cars or bikes.

The other day, about a month ago, I was polishing the leather saddle bags on my Road King. They were a little scuffed so I grabbed black shoe polish (the paste in the little flat tins) and proceeded to polish the bags. My son's bike (a 25 year old shadow) was sitting next to mine. The plastic was originally black by the handgrips but was really starting to turn grey pretty badly. We had already tried restoratives and sprays like armorall and it might have lasted a day or two before reverting to it's ugly grey again. I figured I'd try the shoe polish and see what would happen. I rubbed it in real good and let it sit for about five minutes before polishing it up. Well it's been about a month and still looks decent. In fact so does all the other parts we polished up. It even put a little shine back into the old plastic.

Just thought someone could use this info if they had similar problems. If anyone has a better idea to restore old plastic I would appreciate hearing from you!