do plastic windows weigh less then glass in a car
Yes, but you have to use a certified type of plastic. It has to react in a certain way in a collision. It's also thinner and offers less sound insulation. This is why very few road-legal cars have plastic windows, save for stripped out exotic cars like the Lamborghini Gallardo Superleggera, Ferrari F430 Scuderia, Aston Martin V8 Vantage N24, and I believe the Porsche 911 GT3 RS has some plastic windows.
