Prep 400 Overspray Remover Removes overspray from painted surfaces without damaging most underlying paint Removes paint (aerosol) from exterior painted surfaces such as fleet vehicles, bridges, painted brick and block. Safe for use on Plexiglas" and Lexan". Also effectively removes grease, wax, marker, bugs and road tar from a variety of surfaces. For Plexiglas and Lexan, always use Prep400. Note: Prep400 will discolor auto glare-reducing films.