I did think it had a Mercury flavor...
This is the 1966 Mercury Astron, custom built for the 1966 auto show season.
Correct! The Mercury Astron had a sun-sensitive glass roof that darkened automatically, along with a flexible glass backlight that retracted into the roof. The taillamps were green for normal running, but changed to amber if the driver lifted off the gas and red if the brakes were applied. Derived from a run-of-the-mill Mercury Park Lane, it had a partial vinyl roof, C-pillar opera windows, and fender skirts. The body side trim was wider than a stock Mercury, and the car had no outside door handles. Unique headlamp bezels and hidden parking lamps light made the front of the car look different - sort of like a Chrysler. This is the only other pic of the car I can find.