Valiant Sedan Delivery

I had the same thought, so I did some research. Max's Panel Van is a 1975 Holden HJ Sandman (the HJ was made from 1974 to 1976). These cars had all the options and were the top of the range. The front end has been replaced with the front end from a Statesman. Originally the van would have had a twin headlight front.

Info and picture credit here: http://www.madmaxmovies.com/mad-max/mad-max-cars/max-hj-sandman-panel-van/index.html