The puzzle car shows just a modification by its owner. But in the 1980's, when I was into the old car craze, I've known a common accessory that you can see in the second pic, on a 1958 Oldsmobile. Maybe it existed in the 1940's and 1950's, I don't know. It was that thin steel rod fixed to the bumper. It would act like a spring and emit a "ping" when coming in contact with the curb, warning the driver that it was close enough.