Also I've found British drivers more courteous than Australian and more likely to allow you to change lanes.

Ah, Tangledwood, perhaps you've only been to Sydney. My experience of capital city drivers in most Australian states is that the natives of each city have their own perceptions of what counts as proper behaviour and none of them has much time for the differing norms of other cities' drivers. While I've been relatively successful in adapting to each city as I've spent time in it, I've found Sydney to be the most "difficult" to adapt to.

Cheers, Rowan