Some spray bug killers and other type of sprays will eat right into your isinglass.
Don't use paper towels if you left any dirt on the window it will scratch it.
Do not leave it in your dock box and let it bake the heat drys it out.
For winter try to store it flat.
Spay your vinyl down with water before you clean it get any dirt off before you clean.
How do I get clouds or extreme wrinkles out? - The sun will take out clouds caused by trapped moisture as well as wrinkles over time. A heat gun or hair dryer can be used to accelerate this process
 I all ways use A terry cloth towel and vinegar and water for cleaning my clear vinyl.