That's very interesting. This is the first time over all these years that someone out there has this in a Mustang. In 1977, I bought my first mustang coupe that had them on each side (6RO7T128891). They were white, matching the exterior color (M), headliner and visors, otherwise, a red standard interior, Seattle DSO. When the car was rear ended and totaled in 1987, I saved them and later dyed them red for our fastback. They were useful for the back seat passengers, to help extractions be a bit more graceful... I removed them a few years back because I've never seen them or found any supportive documentation. Guessing they were a dealer installed option, for certain not common. They're still laying on the bench in the garage....
