Fifth wheel / parallel park in 1933

A fifth wheel is used to help parallel park in 1933.

Brooks Walker was the inventor of the fifth wheel and received a patent for it in 1935. He spent the remainder of his life trying to get the automobile industry to adopt his invention.

In 1952, Walker tried to sell it to Cadillac for $175 ($1,957 when adjusted for inflation), however, they refused because the device took up almost all of the trunk space. The next year, he was able to add the fifth wheel without sacrificing trunk space, but Cadillac still declined.