Blue Coral also has a similar product called Plexiglass/Plastic Cleaner/Preserver. One of the uses listed on the back is "restores optical clarity to CDs". Really does the trick for scuff marks and light scratches and seems to make the surface more resistant to fingerprints. If the plastic protecting the instrument panel in your car has dulled from cleaning it with a paper towel, this stuff will make it disappear.
Good tip about the two types of microfiber cloths also, I'll have to try those.