The screen on the DT300i is poly resin, plexiglas, not Lexan, a poly carbonate. Plexiglas is really soft where Lexan stuff is really hard. The polyester resin, plexiglas, products may be shined up with the same stuff you use on paint but the final glop to use is a wax to fill the really small scratches. Airplane guys usually use Mirroglaze (spelling may be wrong) but it builds up and leaves a yellow hint of tint when it gets kinda thick. Our airplane guys started using the cheap spray wax for furniture because it was cheaper, did not build up and worked great. Small aircraft generally use Plexiglas for windows and canopies. Use the lemon scented stuff since it smells really good!
Karl