I heard that expression for the first time in Brisbane as they call doggers a digger driver or something. A guy from the UK told me what it means in the UK. So I don't think it is that common here. I could be wrong, Actually I think I am. There is a place in Wellington called Wrights Hill where a lot of couples go to make out. I don't think its dogging as such as but have had sex up there in our car while others did the same. Very sexxy knowing what was happening in the next car. Couldn't see though as the windows were all steamed up!
There is a bus that goes up there, so you have to time things to work out in between the buses or at night.
Could be a great dare for a party!
Goodluck