When we purchased our '92 Civic project a few months ago, the headlights were so dimly lit at night that it was actually scary driving the car. The lights were so gunked up and filled with dirt that cars behind us kept flashing their lights at us thinking our lights were off. Once we bought a set of plastic JDM headlights we decided to not only restore them but also change the bulbs with Sylvania Silverstar bulbs.
There are tons of headlight restoration kits currently sold on the market that you and I have tried at one time or another. The problem is that they include sanding off the OEM UV clearcoat followed by a polishing process. After a few weeks the wax will eventually dry up and revert back to a set of cloudy headlights. Two parts included in the Sylvania kit that we haven't seen in stores before is the (first step) surface activator and the (final step) UV clearcoat. Yep, with this kit you reapply a UV clearcoat barrier just like all factory plastic headlights.