Good to know you enjoyed the story, StephenCraven. When the Non-US GM cars planned for 1964/65 are lined up (1964 Opel Kapitan prototype, EF Holden, Vauxhall Viva and Opel Kadett) you can clearly see that each follows a similar rectangular design theme. They look-alike. In fact,they look like cars from the 1950s. The Viva and Kadett were allowed into the showrooms, where as the Kapitan and EF/HD were subjected to complete change, as the two colour images demonstrate.My reckoning is that Holden's boss Harlow Gage had everything to gain by letting Bill Mitchell design the EF/HD. If it succeeded Gage would share the success. If it was not a success, he could say "the American's did it." If he stayed with the locally designed EF and it failed, then his career would most likely have been significantly curtailed. In summary, the decision he faced was not difficult to make. Go with the US design. As it turned out, Gage left Holden to go back to the USA in late 1962 and David Hegland took over. And as we all know, it was Hegland's initials, DH, that were reversed to form the model code HD