I once used two 3" cloth buffing wheels back to back on a hand drill with jeweler's rouge. This was a set of taillights from a recycling yard. The kind where they had pulled the lights and stored them on metal shelves, face down of course. They were all scratched up. Made them look like new. Unlike doing it by hand, any lettering on the lens fills up with polish so you have to detail afterwards.

Another episode was the thin plastic rear window of a Sunbeam Alpine convertible. I think the thin plastic was damaged all the way through so it only gave miner improvement.