 Complete the following phrase:  On 20 May 1956, Johnstons world changed. He was part of the Cunningham team that raced at the Cumberland circuit, in their D-Types. They were joined by amateur driver Walt Hansgen. At the start of the race, Hansgen raced away and left the field behind to win, but Johnston failed to finish the race. A fortnight later, Hansgen would also be a member of the Cunningham team. At Road America, both Johnston and Hansgen rolled their D-Types. After the disaster of the 