I have tried all kinds of stuff and the current best results came from Blue Magic metal polish and a small buffing wheel in the cordless drill.
Squirt a bit on the lens, rub kinda hard with just your fingers, let it set for a minute or so (not till dry!). Squirt a little more and spread it around then low speed with the wheel. Circular pattern seems to work best.
Escorts, P71, 96 Mustang and a couple of Nissans still look great. I am looking for a local fellow that applies a UV coating that protects against stone chips and such.
Bruce