original depression era pressed heavy gauge single-sided steel oversized sign letter removed from an old self-serve car wash located in the south loop. the cobalt blue porcelain enameled finish remains in excellent condition, considering age. likely fabricated by the burdick enamel sign co., chicago, il. measures 18 inches in height. the first conveyorized automatic car washes appeared in the late 1930's. conveyorized automatic car washes consist of tunnel-like buildings into which customers (or attendants) drive.