Retroautos: You've got the Opel 'Rekord' (series E) right for the body-shell but the front was grafted from the Opel 'Senator' to accommodate the larger Holden six and eight cylinder engines - which then gave it a similar appearance to the Opel 'Commodore' (C) sold in Europe, the Vauxhall 'Viceroy' sold in the UK and the Chevrolet 'Commodore' sold in South Africa. Overall, the body was strengthened substantially in order to withstand the harsh conditions of the Australian outback and the total cost of development was reported to be over A$110m. I hope the extra information helps but I stopped short earlier because I thought this info would be readily available on Wikipedia as previously stated. Here's an Opel Senator from the same period.