[RA1John]

The 'Bird Glass' will likely remain a mystery unless someone comes across GM, PMD, or PPG documentation specific to this feature.

After researching this with other enthusiasts over the past 35 or so years, all we really know is that the glass was not a special order, nor was it connected to any particular style, trim, or option.

They've been found on fully loaded cars and very basic cars. Ram Air conv, 6-cyl coupes, custom trim, standard trim. Tinted & clear. If one were standing on the line at Lordstown in 1967, they would have seen one car get the glass, while the one directly behind it did not. Quite likely this feature was eliminated due to either cost or, upcoming (Jan. '68) Federal Safety changes pertaining to side view visibility (also the reason for the SV mirror & outer door skin design change from round to rectangular).

PPG apparently only produced this glass in (3) batches during the end of 1967: Sept, Oct, Nov. (only 3 different date codes have been found).

According to Registry files, most surviving cars that have Bird Glass were primarily built between the end of Oct. and middle of Dec. (heavy concentration in Nov. timeframe). Some cars have been found with this glass going into the spring of '68.

While there have been repro 'Bird' decals made over the years, I'm not aware of any repro glass with the Bird ceramic baked in the glass as originals were.