Glass rear windows greatly enhance rear visibility. They are not prone to scratching, cracking or yellowing due to exposure to the sun. 1965-1970 rear windows have a visible urethane folding seam. 1971-1973 are solid glass. 1964 - 1966 must use 67 - 1970 convertible well liner. 1965-1970 folding seam carries an 18 month warranty against splitting or separation.