From Van's website
Cleaning And Use Of Liquids
For general cleaning use Dawn dishwashing liquid or equivalent and water followed by a clear water rinse. To prevent water spots, blow dry with compressed air or wipe dry with soft cotton flannel. Plexus, Sprayaway #848 Industrial Plastic Cleaner, or All Clear can also be used for day to day cleaning. Grease, oil, tape residue, etc. may best be removed with Mineral spirits, refined kerosene, white gasoline, naphtha, or isopropyl alcohol. Wash approved solvents off of canopy with Dawn dishwashing liquid and water.
It is best to avoid using products that are not specifically
formulated for acrylics on your canopy such as Rain-X or Lemon Pledge.
CAUTION: DO NOT use Loctite, aromatic solvents, acetone, benzene, ethyl acetate, carbon tetrachloride, lighter fluid, lacquer thinners, gasoline, toluene, window sprays, concentrated alcohols, keytones, scouring compounds, ammonia, or 409 cleaner on or around acrylic or Lexan canopy materials.
CAUTION: DO NOT allow electrical tape or auto fuel to come into contact with Lexan as it will also cause crazing. This is a particular issue to beware of when refueling the RV-12.