^That'll be a hell of a rock and you're better off getting a pair of new glasses so you can see the dump truck ahead of ya!
Truth is it's too late to put a 3M bra on it if you didn't do it when you get the car brand new.
I just polish my lens with this stuff so it doesn't go yellow on me.
http://www.plexusplasticcleaner.com/plexus.html