BART was not one to miss the bicentennial celebration; they replaced the front logo of about a dozen A cars with the official Bicentennial Logo, along with smaller versions of the same logo on the sides below the Y end car number. It wasn’t to the extravagance of many conventional railroads with their specially painted units, but it was still a nod to the 200th Anniversary of the founding of this country.
Picture from Pacific News, July 1976 issue
"The Two Bagger" is meant to be a place to store more "blog" style posts on various cars, pictures, and random tidbits. At BART, a "two bagger" is a rather informal name for a two car train. Two car trains rolled in revenue service back in 1972.