It does seem like an unusual name choice, given Chrysler Australia would have had access to a variety of luxury name plates (Imperial, Newport, New Yorker). It was likely chosen because it was a very "now" phrase in the late sixties that included pop stars, politicians, movie stars under one "very important person" designation. I used to see them occasionally as a kid, the only thing I really remember is the flowery VIP badge. All of those big, luxury models ended up as poor mans hot rods for the people who wanted a V8 but couldn't afford the performance models. I think that contributed to the demise of most of the Broughams, VIPs and Fairlanes.