If you want to do it the cheap way try Turtle Wax Colour Back (if you have it anyway) or brass polish (Brasso in GB?). I use the latter about every 5 years and am still on my first plastic windows. O.k., they are a bit brownish after more than 40 years but still perfectly transparent. A buddy uses toothpaste with good results.
A product I can NOT recommand is the one of Meguiars. I tried it on a Jeep Wrangler. Absolutely no effect after rubbing for hours.
Admittedly the Wrangler windows are a harder and thicker plastic than the Morgan's.
Frank
