Brisbane BMW won't negotiate the price.
However, I called up toowoomba bmw and here are the prices I got:
$2663 for the 2 year unlimited km
$2991 for the 3 years 75,000km
The difference is the first one is "bmw" branded under written by allianz and the second one is an allianz cover (for bmw). As far as the dealer tells me, the second one doesn't have road side assist and doesn't cover some trim items but otherwise it's the same. You still go back to your dealer and they do all claims. eg. if turbo goes, both warranty will cover it.
I dare say anyone even from sydney and melbourne can call up toowoomba and get the warranty there as the guy i spoke to was very nice and offered discount without me asking, and the warranty is not dealer specific anyway.