Alex,
I know its a pain in the arse and it may sound cliche but just be prepared to walk and let them know you are talking to other dealerships (even interstate) and be ready to place a deposit there and then. I went through the same thing on my deal the other day. The list price on my car driveaway was 94k, I managed to get it for 83.5 (with an iphone adapter thrown in)
Let them know that you would service your car at their dealerships so they could recoup some money that way! I know it sounds like bullshit but it may work!
I'd even try a place like Geelong BMW. They don't sell a great deal of BMW's so to keep their BMW franchise they generally go pretty low on a driveaway price to get a sale through.
Hope that helps mate!
Steve