To be honest, it sounds like they just didn't do their homework prior to setting up. You can't just assume a certain set of financial conditions will stay the same, regarding currencies etc, and the Astra size market was already fiercely competitive.
While I would have loved for Opel to get established in Aus, and then cross the Tasman too, it was as unlikely with their market penetration strategy this time as it was back in 1990s when they were last importing Opel branded models to NZ. I'm not sure if they were even that prevalent in Aus back in the '90s, from the numbers of owners I hear about over there.
To look on the bright side, we didn't gain anything over here, so haven't lost anything either!
Might be time for a press release!